GM 10-bolt axle rebuild complete!

all right well give you guys a brief introduction while um i'm going we're trying to get people set up here and uh basically what i'm gonna do is i'm gonna go through these axles and i got this mock-up that i've made years ago and actually it wasn't that many years ago just about a year ago and it kind of shows the the insides of the rear axle you might have seen this if you've seen a video of mine got a ring gear our pinion gear so the big thing that we're going to go through when we're setting up is we're going to first set up our pinion depth and our pinion depth shim is located right in there on the gm now some of you guys thought we were going through the dana first but i don't know why but i decided to do the gm axle first and um but it really doesn't make a difference the reason why we go through the gm and the dana is because the really one big difference is that gm uses a collapsible spacer and the dana axles that we have they use a shim in this spot and we'll see what that does here in a second but this is the axle assembly as you know we would see it in a vehicle and what we're going to do is set it up and the location of these gears of the ring gear and the pinion gear is extremely precise so positioning this pinion gear and this ring gear in the right spot is essential that's the reason why it's such a big deal i talk about that there's really only four steps to setting up an axle and it's going to be pinion depth that's the first step that's what we determine the second step is pinion preload that's going to be the clamp that's on these bearings the third step is side bearing preload and backlash to make sure we have the right clearance between these gears and then we do a contact pattern so that's four steps it sounds pretty easy and it is but there's about a million sub steps so don't let the four steps part throw you off like it's super duper easy a lot of students struggle understanding this concept and it's it's probably the details that get them more than it is the actual overall concept but the business position of this pinion gear and this ring gear have to be pretty close together you know if you're off maybe with the pinion depth two or three thousandths of an inch either in either direction from where it's supposed to be you're gonna probably have a noise and same thing with the backlash backlash is really important clearance if you're too far away you're going to create a noise and if you're too close you're not going to have enough room for lubricant you're going to overheat the gear set so yeah this is basically a a the cutaway of a gm axle front to rear you can see the transfer case and the transmission so the engine which isn't here would deliver torque through the transmission through its gear ratios to the transfer case if you have one you know this is for four wheel drive go through the drive shaft i then would drive the rear axle assembly now the axle semi cut these down and uh put the axle shut you'll cut these axle shafts down so they can fit on a bench easy now one thing that you'll see when we do this bench work is that the i don't have the axle shafts in and before you take these parts out you actually have to get the axle shafts out and that would i've seen students believe or not i've actually kind of done it myself embarrassing to say but you know you start taking these things apart and try to get the ring the differential case out it doesn't want to come out and then you realize well i didn't pull the axles out you get so used to working on these things on the bench the way we have them without any axles in them that you can sometimes forget something as silly and simple as that but anyway to get that the axle shafts out on this design this is a eaten locker and this would be the same as an open differential or the same concept is there's a c-clip that's located in there and i have to pull this pin out there's a bolt that retains that pin and when i pull that bolt out i can push the axle shafts in a little bit let the clip come out and i can pull the axle shafts out so that's basically what that'll have to happen and as you can see this axle assembly that i have right here doesn't have the axle shafts in it and i actually chopped these things off because i used the ends of those to finish building that so anyway a little uh long and short of it if you guys could post a comment on whether or not you can hear and see what i'm doing right now that would be helpful just to make sure that everybody is doing all right logged in as i see on facebook there's a couple people saying it's working this is so exciting thanks ken way out there and where are you nevada now um tyler nice to see you're not even in the drivetrains class but you're watching us i appreciate it thomas man you that's a love to have graduates watching this we need to get justin morgan on here he's the one that made me wear my pink shirt today because he promised he'd watch if if i did that so i'm glad to see you guys are on there and i got a thumbs up on the um on youtube from manual rise okay excellent so yeah if you could give me like if you're on facebook give the thumbs up or if you're on youtube a comment whatever just to make sure that everybody's seeing this okay well this is the axle this is a gm it's called a 10 bolt because it's got 10 bolts holding on this cover there's actually two different sizes of these 10 bolt axles the the um a smaller one which is like a seven and five inch diameter ring gear that's going to be used on smaller vehicles like your s10 pickup trucks and even your camaros had it because they didn't have much room for an axle assembly i'm talking about the older camaros and then there's the larger 10 bolts which are more common that you'll find in most half-ton pickup trucks and we've got a a variety of tools to help overhaul this now a lot of people would ask especially when you start going through this thing you start working on it you'll um and as a student you'll probably be like man there's people that like to do this stuff in the driveway in their garage or something like that and and they have a hard time believing that that can be done it is difficult to do mainly because there's a few things that will pretty much require some special tools the big thing is is to get the bearings off you need to press the side bearings you can usually use pullers the pinion bearings you'll you might be able to destroy the bearing and use a puller to get it off as long as you're putting new bearings on no big deal but if you have to pull that bearing back off to change the shim you might run into a situation where you're going to destroy another new bearing now you can get presses pretty cheap harbor freight sells them for between 100 and 200 dollars and um three jaw pullers or two jaw pullers sets they're cheap so with the advent of harbor freight really and and you know us guys we love to buy tools right so it's not a big deal to go out and buy some tools to keep in the garage i don't really say that this is something that a do-it-yourselfer couldn't do i think anybody really could do it but you'd struggle a little bit if you didn't at least have a pretty good size press and um you know a puller set and also this pinion nut that we're going to be taking off that thing could be torqued down it could have 300 foot pounds of torque on it so you're gonna have to have some muscle maybe a cheater bar you might have to sacrifice something that if it ends up breaking if you're lucky like me you'll have larger tools you know like a three-quarter drive breaker bar or something along those lines but i should probably wear safety glasses when i get on this because you know how i get but anyway um we're going to go ahead and start taking this thing apart but one of the first things that you're going to do is some disassembly checks and just really you don't have to do this but it's kind of gives you an idea of what this the condition of this axle was before you take it apart and i'm going to show you on this board i have i don't know if these will yeah i should come into view i'll keep it right up there there's four steps to setting up the uh this axle pinion depth pinion preload side bearing preload and backlash and contact pattern we're going to go through all four of those steps but first before we do it i'm going to want to just check a few things one of the things that we're going to check is the contact pattern of this gear and in order to do that you're going to take some of this paint and this is gear marking compound when you buy a new a set of gears it comes with a little bit of this gear marking compound and a little brush so you can smear it on this is a gm part number i guess uh for those of you guys that do it a lot you might want to okay let's see boom this is the gm part number i don't know if that'll come into focus or not i'll tell it to you it's a one zero five two three five one it is basically titanium dioxide paint titanium dioxide paint you can get at an art store or something like that now you'll see some people say paint all the teeth well i don't like to do that because it makes a mess and kind of waste the paint and for what we're doing we don't need to have a bunch of teeth painted so we're just going to paint a few teeth here and i like to do this before and after if for no other reason for education's sake that if we have to make an adjustment we could see what the how the pattern changed and i could tell right now by moving this gear there's a lot of backlash i can hear it and we're probably got we got over 10 000 so it's excessive on the backlash matter of fact this axle should have never if this was built we should unless they were experimenting to see what a lot of backlash would create um it should never have gotten to the point where you would do a contact pattern because if you have too much backlash why would you bother doing a contact pattern you'd want to lower that backlash down because i'm going to rotate this set of gears down where my pinion is i'm going to rub them back and forth now just doing it by hand like that usually isn't going to have enough force to actually make a a good impression on the paint so you're going to have to use a ratchet and a wrench and you're going to use the wrench on a ring gear bolt to move it back and forth and you're going to use this ratchet to provide resistance now this is one of those things that can you tap your head and rub your belly at the same time because you're moving in this direction with this hand and in this direction with the other so if i punch myself in the face you guys will have this on video and you'll be a laugh at it it also likes to slip off unless you got all right oops see i'm going to pull that wrench right into my jaw if i miss that'd be a good blooper reel there huh so i'm providing resistance so i can really wear those two gears together now i only did it in one direction so i'm have to flip my ratchet over and do it in the other direction because i've got two sides to these gear teeth right it's going back and forth so now hopefully i did that in the right spot okay so i did because sometimes you'll do it you'll realize that you're in the wrong spot or you're missing the gear i'm going to zoom in on this so you can see that i'll pattern a little bit hopefully that shows up all right stay there boom oh maybe i'll rotate my gear a little bit you can see this is the gear surface right there and just to remind you guys of these gear tooth names anything off to the outer part of this gear is called the heel anything towards the middle is the toe imagine your foot standing on that gear and it would basically be like uh you know your heel would be on the outside of the gear and your toe would be on the inside i'm going to zoom out so i can see a little bit better there okay now the towards the root the base of this tooth is going to be the flank towards the top is going to be the face and we call the pitch line smack dab down the middle now the reason why i'm showing you this side is because this is the drive side this is the side that's being pushed on when you're driving down the road and accelerating this is one of the things that you also hear a lot of people talk about contact patterns and they'll look at the dry side and the coast side and then sometimes you'll see pictures where people will be only showing the co-side and if you're going to build an axle you're going to want to build it so that the drive side has the best contact pattern sometimes you will have a good pattern on the drive side when you look at the co side it just doesn't look ideal but what would you what are you going to do you're not going to sacrifice the drive side pattern to make the coast side look better because the drive side is seeing the torque from the engine so anyway right now what you can see this pattern right here is coming off the heel see how it's coming right off the end of the gear tooth you can see it's clean the part that's cleaned out is the part that the gears were meshing on so it's running right off the heel on all these teeth and it's off to the face also so it's kind of going off to the corner of this tooth this one this gear would definitely make a noise whenever the contact pattern comes off of the the gear tooth it's going to create a little ringing sound so it create a whining sound going down the road it wouldn't be good what would an ideal pattern be an ideal pattern would be offset towards the toe definitely not towards the heel it would be in the middle of the gear meaning centered across the between the face and the flank i like to say that the gear is going to spend just as much time on the face side of the pitch line as it does on the flank side of the pitch line and the reason why is because sometimes these patterns aren't perfectly oval sometimes they're kind of like a parallelogram or something and to stare at those you're trying to figure out is it towards the faces towards the flank well if you draw an imaginary line down the middle of this gear where the pitch line is as long as there's just as much wear or contact below the pitch line as there is above it you can consider it centered from face to flank so it should go half of the length of the tooth be offset towards the toe not run off the gear in any direction and spend as much time on the flank as it does the face so those are kind of some general rules as you can see this would fail the contact pattern because it's pushed off way there towards the heel and even off towards the face so that wasn't zoomed in too much for you guys to see it but that was uh that's that if you guys have any questions make sure you post them up i've got um our fearless leader of the automotive program is over here he is monitoring the the the computers for me so you could say hi to everybody hey everybody and he's making sure that um well he's making sure that if there's any questions that they don't get lost or skipped or something like that now the next thing i want to do before i tear it down is check my backlash the actual movement or the clearance that i've got in this gear if you guys remember backlash is there because we need oil room for oil to get between these gears and it's a critical measurement it's a critical part to setting this axle up and as i mentioned before that if unless you're just doing an experiment there's really no reason why anybody should have done a contact pattern on this gear when they put it together with loose backlash and i could tell just because i've jiggled these gears enough times that that this backlash was high all right now this thing's this is a little snake with a dial indicator yes this is another one of those tools that you will need to have if you are working on these you can't guess at backlash and some of these measurements but if you're the type of person that's willing to take on an axle assembly in your backyard you're probably the type of person that's also willing to go out and buy some tools and like i said if love it or hate it harbor freight has really kind of helped the backyard guy out because tools are a lot cheaper and if you're not using them every day you probably don't need to have the most expensive tools in the shed let's switch to the boom this has got the dial indicator on it i don't bother zeroing it because i can do simple math in my head not to sound like a like with an ego or anything like that but you can see i'm going between 14 and 29 so what is that that's 15 thousandths of an inch so that's way too much backlash if you look at the specs and of course you'd always want to use your service information i haven't looked this up and i always forget even though i teach this every year but the backlash is supposed to be probably i'm going to guess between five no that's sound different um it's gonna be between like five and eight or six and nine thousands right there five and nine thousands so backlash nice zoomed in there we go so backlash is between five and nine thousands for all new gear sets i don't know why they say that because it's not like they give you a spec for used gear set but fifteen thousand now this is just in one spot i'm gonna want to go through and check it in a bunch of different spots i usually rotate the pinion about a half of a turn and then i do the check again i'm going from 15 to 20 or 5 to 20 so that's 15 000 still and then i'm going from oh let's see 12 to 26 there's fourteen thousands dude can you show on the dial indicator where it's positioned at on the tooth they don't see that in the video okay yeah that's a good uh um point somebody mentioned can i show on the video where i'm contacting on the tooth i was zoomed in too far so i am touching i'm touching the drive side and the reason why i'm on the drive side i could be on the coast side but if you look the co-side of this gear has got a kind of a steeper angle the dry side of the gear is more like parallel to the rotation since i'm moving this gear like you know this direction i'm on the drive side because it's it's all that movement is going straight into the dial indicator if i was on the code side and kind of hitting it straight on i wouldn't be measuring the true you know rotational i don't know what direction you call this i guess a rotational direction of this gear set so yeah i'm on that and that's why when i lifted it up and i moved it half of a turn i get back onto that gear and then i'd measure it again and pretty much everything is between 14 and 15 000 of an inch but that is a good question where was i measuring the gear i zoomed in too far and and now this is also another thing that messes people up sometimes the preload is set up really high on these bearings and when you go to move them like right now if i go to move this just with light force i don't get anything you might have been able to hear go clunk clunk clunk when when i'm when i'm forcibly moving it but if i just grab this gear and move it you don't hear anything because there's a squeeze there's a clamp on these bearings there's preload on it so you actually sometimes have to grab it and make sure there's movement there um especially after it's been set up because once it's been set up these the side bearing preload could kind of get you there all right so i got the gear contact pattern off to the face and towards the heel and i've got my backlash which is 15 14 15 000 sets high so now i'm going to go ahead and take my bearing caps off i'll zoom out a little bit more actually before i zoom out i'm going to zoom in and i'm going to show you guys these things have already been marked these bearing caps and kind of like main bearings on an engine the caps only go on in one spot i mean they'll go in in other spots but they'll go in and it'll be wrong they get machined in place so if i take this cap and put it on the other side i'm going to have alignment issues and i might put the distort the bearing and have an issue with it so the first thing i like to do is just take a look at an axle before i take it apart and see if there's some factory markings indicating which direction these or which side they go on if not you want to put a mark yourself a little chisel punch a little pin punch like a a letter punch but you can see this has a center punch here somebody put a dot there and somebody put a single dot there and on the other side even though you really only had to do probably one side on the other side somebody put two dots and two dots so that way you know they're in the right um on the right side in the right direction and so forth all right i'm going to pull these caps off this is on these gm10 bolts it's still i don't know we don't this is the newest axle i probably have i think and it's in early 2000's i don't know at what point but they probably switched to metric i'm just guessing but these are all standard sizes not like you couldn't make a metric ratchet work on it but or a socket work on it this is a 5 8 of an inch you can do this in the car it's i just do it on the bench because that's where our units are matter of fact most of the units we have are chopped down so they don't take up as much space we have a little rack that we store them on now if you're doing it in the car i always recommend you take these caps off and then when you're done take two bolts and just thread them in here you can probably guess why i have you do that because if it's in the car and this is all open and remember this this would be positioned i don't know if i can slide this but no i can't it's too tight but this would be like up this way so this opening would be facing out so gravity could let this stuff fall out if it was loose well if you thread this in a few turns you can still get this out but if it falls it's going to land on these bolts and it's not going to fall and hit the floor that is a big that's gone forever that's a big deal now i can't just go in there and lift this out it's in there tight if you remember these bearings are squeezed they're preloaded by these shims that you see on either side here so how do i get this out sometimes you'll see people prying on it they'll get a big old pry bar and you might be able to get underneath the diff case and pry it out you might not have room to do that depending on how the vehicle's set up or any if you don't have any openings there is a trick that you can do and you have to do this you put a wrench on a ring gear bolt and it has to be on the top of the axle housing the way this is mounted this is the top and you're going to be like well how do you know that i spin this around a little bit maybe you can see see my my opinion is offset to this side to the you know away from me this would normally be the bottom of the vehicle so they offset the pinion on these high point gear sets down that allows the drive shaft basically to sit a little lower and it creates less of a clearance issue so i can look at this and say okay this is the bottom of the axle housing this is the top of the axle housing i'm going to put a wrench on a ringer bolt on the top of the axle housing i could try this by hand it might not work but if i rotate the drive pinion it might spin it right out now it still didn't want to come out if you heard my shoulder pop because i tried too hard i'm old man so i'm going to spin this with a wrench or a ratchet or you know a breaker bar or ratchet and you're going to see this this diff case pop out now remember i mentioned to you before you want to have the axle shafts out this is where you can get ahead of yourself but so see how it just spun that out and that kind of nice doesn't come all the way out but it usually comes out far enough so you can get something under these shims and get the shims out of there as soon as you get some of these shims out then then it'll all be loose so really once you get one shim out it'll be easier to pull all these out so i know my bearing caps are marked so i can put those kind of out of the way and maybe i'll go back to the all right you see me live again here so i'm going to pull these out hopefully i won't lose any fingers in the process this is one of those parts where when you take it out you hear things falling on the floor because it's hard to lift this out this thing probably weighs i don't know probably 30 pounds so you don't want to get your fingers in the wrong spot now if you look it's like man there's a lot of shims in this thing that's actually not typical usually these are the shims i pulled out right here um yeah we got this going on so i got four shims on each side that is not typical it's not usually how these things are set up and usually you just have one shim when you take it out for the first time here's an example of it this is a cast iron shim basically the one that comes from the factory and you can see here it's just a one piece and they figure out the size that it needs and they've got little markings on them and so forth but what they're the reason why these are um that they let me let me take a step back when you replace these you end up putting two shims in there and this is the way the oe does it so you don't necessarily have to do it this way when you buy a new ring and pinion it comes with the install or if you buy the install kit it comes with shims to put in place of it and they're a little different than this but like from general motors you would get this which is called a service spacer they're all 170 thousandths of an inch thick and then you put a surface shim next to it so the combination and then the shims will go from forty thousands to a hundred thousands so you have the overall thickness between these two being two hundred and ten thousands all the way up to um 270 thousands so they end up replacing these shims these one-piece deals there's they say don't reuse them because they're cast iron and they can crack i i've used them um really they're not going to go anywhere so it's even if they did crack they're captured between the bearing and the uh and the housing so i personally would never throw these out because sometimes you are missing a shim or something and you need the size and you might just happen to have a selection of these over the years of rebuilding them and then you have the right combination of size so use it so this is uh what they're supposed to have now the reason why i'm gonna guess that we've got a stack of shims here is if you take a look at the diameter of this shim it fits in there nice and then if you compare it to like this service spacer it's actually a little bit bigger the shim is because at some point gm they made their side bearings larger and so a lot of these kits these shim kits that i've got don't necessarily work with like these service spacers if i tried to use this in here it wouldn't fit right probably part of it would try to fall into the axle tube so i can't use these on this so my guess is whoever set this up last i've got some of the larger shims but they ended up making their own basically service spacer and you could do it like these are all 60 thousandths of an inch so if i put 260s and a 50 together i got 170 000 so i'm just wasting a lot of shims so that's the only thing you can buy these i don't have the part numbers or anything like that but these and this is something we probably need to get for these act this is the only axle i got that's got the bigger gears uh bigger bearings but you know basically getting the 170 000 service spacers they're available and they replace the cast iron all right enough on that all right got that out now the next step is so my diff case is out i need to get my drive pinion out see i told you something that was that bolt that fell in there let me get that down okay all right so here's the bolt that was one of the uh capped bolts we need to loosen this up this is that pinion nut this thing could have hundreds of pounds of torque on it because when they set these up general motors they have that collapsible spacer in there and established preload we'll see that here in a minute so when you actually take this apart for the first time this thing is going to have a ton of torque on it because in the process of of of tightening this pinion up at the factory if somebody went through it before they have to crush that sleeve down and crush it to the point where the um the the bearings are spaced the precise amount away from each other so you get the right preload and that usually requires a lot of torque switch this boot our switch camera positions here so this tool here is a yoke holder it keeps allows me to hold this yoke assembly in a position there are other types there's types that you can put bolts and so forth into and then i'm going to use my breaker bar like i said the breaker bar might not be enough i know it will be on these because we don't reus we don't put new collapse collapsible spacers in every time we do this because it's kind of a waste and we tear the threads up on the pinion because of all that torque it takes to crush that sleeve you'll see what i mean about that sleeve here in a second i'll show it to you but the um so when we reuse these sometimes we'll tap out the collapsible spacer just to kind of reuse it but it won't take a ton of torque for this one all right so it's a little bit more but you know i'll just have to get tough with it okay there we go i'm gonna guess it was about 350 400 foot pounds but i got it all right no sweat i've seen students it's kind of funny to watch they'll um they'll both they'll have one person holding the yolk holder one person pulling the breaker bar and even if you guys are both strong the balance is what screws you up you're almost better off doing it yourself and you wouldn't do it like to try to loosen it in the position i have it now you'd want to have it like right next to each other like this and even better more like this why because if i'm over here and it breaks loose i might rake my knuckles across this tool and leave a layer of skin on there i think that's what this is right here somebody's skin i'll peel it off it's pretty gross but okay so let's spin this guy out now this thing is tight coming off all the way because the nut they use from the factory these pinion nuts have this distortion that they do to the top of it i'll show you that so this is a that pinion nut and if you look close at it it's not perfectly round they crimp in in three spots and that makes it tight so that way it's like a locking nut okay now if you look this just doesn't fall apart just doesn't come out on us so what we have to do is tap this out and you have to use a brass drift and a hammer and i'm going to go ahead and start tapping this down now normally you would have somebody put their hand underneath there and kind of catch the pinion um i'll see how this goes [Music] i tell students usually put their foot underneath there to catch it but they don't listen to me and if they start dropping things i tell them to bring their pillow from at home so that way they put it underneath the whatever they're working on it's about going to come out i'll probably be able to tap it the rest of the way now mr bearman was back there he's freaking out because he just can envision the chip painting uh of the paint chipping off the floor and it's freaking him out but i caught it it's all right don't have panic attack but okay now look i'm going to take this um this is a yoke right i'm going to take it off i'm missing a seal and the seal is normally here but because these are uh units that we go through in class um there is no seal so normally this would come out and i would have a seal and then my bearing so this is the rear or front pinion bearing this is the yoke when i tighten the nut down it pushes that front bearing towards the rear that's going to end up pushing that bearing try not to drop all this stuff it's going to end up pushing this bearing up against this spacer start crushing that spacer and it's going to bring these two bearings closer and closer together once these bearings are close enough to the point where they are pressing up against their bearing races tight that's when we get our preload and we'll see that when we go back together with it but right now we're just taking stuff apart so at this point we have our axle housing disassembled taken apart and if i were rebuilding this thing from from a scratch just like you'd be doing if you overhauled this thing you'd take the brass drift and you'd be pounding out your bearing races this would reach in there and grab that rear outer race pound it out going from the other side and pound the other bearing race out we don't need to do that because this is just a little demonstrator unit but if you got a overhaul kit and come with bearings you'd want to replace obviously all the bearings now on the differential case this is right here in this spot right there you can see they put a little notch a little bit there for you this gives you room to put a two jaw puller kind of right into that spot and you can put one jaw and one jaw on the other side put a little spacer there and you can pull these bearings off it's really nice when the manufacturers give you those little slots to go into if they don't then what ends up happening is you have to use a bearing separator like we're going to do here on the pinion bearing and you'll probably destroy that bearing i've actually gone through like on the danus you'll see tomorrow they don't provide this little spot but and i've done something different on that but on the ones that we've done for live jobs i've gone in there with a die grinder and made little notches because the the shims on the danes live between the diff case and the bearing so if your shim combination isn't right and you have to change it you have to take that bearing back off well here if i have to take this bearing off because i'm replacing it putting a new one in from the kit if i destroy it no big deal i put a new one on and i'm good to go i'll never have to take it off again but on the dana's or on some other axles depending on where they put their shims you'll have to take that bearing off again that's no good all right so now we're at this point everything's out of the housing let's pretend we just replaced these outer races now i've got to go through and i'm still disassembling but i got to go through and i got to get this rear pinion bearing off there's a shim that lives under okay i'm not underneath my camera there we go there's a shim that lives between the head of the bearing or the head of the pinion and the bearing it's right there in that little groove you can see it's silver in there that little shim is in there and i need to know what size it is this is one of those things where if you were rebuilding these [Music] in your garage or your driveway or something like that and i say you need a press if you're like well i'm just going to buy new bearings and a new pinion and i'll just pound a bearing i don't need to press the old one off you do actually because you need to be able to figure out what size shim this is if you remember from the lectures online that we will use and i'll demonstrate using special tools to set up this axle but the the in most cases you're going to reuse the shim because the shim that's in here makes up for the differences in machining in the housing more than it does the differences in machining and the pinion and the ring gear the reason why i say that if you look this dry pinion is 100 machined and i'll guarantee you the equipment that they're using to machine this ping pinion gear is very high tolerance there's a precision piece of equipment so when they make this it's going to be pretty good um if it's off it's probably only a thousandth or two in either direction that probably wouldn't screw you up sometimes the manufacturers will go through and say yeah we made that one a little too small or too big and they'll put an etching on the head of the pinion this eight and a half inch gm doesn't do that the newer ones do they're called variances and you will basically adjust your pinions shim measurements or even if you're replacing it you'll adjust it based off of that variance but on this axle on this gm one here we don't have any variants so i'm going to take us over to the press and we're going to press that off if you got any other questions so far what percent are we at 20. oh we're good right now once i go to the boom if we could switch it out all right we are i know you're probably getting a close-up view of me right now but we're at the press and i am going to put this is a little mini guillotine here i'm gonna put this um whoa another thing that's gonna cut your fingers off if you're not careful got a lot of those around here so this is one of those uh tools that you have to respect quite a bit uh now these pressing these bearings off isn't that big of a deal the hydraulic press man they can create 25 tons it's 50 000 pounds of force and you don't want to be around something that shatters or breaks when there's 50 000 pounds of force on it so just kind of realize that when you're working on around the press have a little respect for it i've almost peed my pants a few times working at this press the last time was pulling bobcat axles off the the hubs off the axle shafts that took pretty much i got it to the to the red zone the danger zone and then i had to put a torch on it and then when it finally popped off it scared the death out of me but i even made a little scatter shield around it because i was worried it was going to kill me but i'm here to live and show that i lived through it now this is an adjustable press this is not going to be your harbor freight special if you end up getting one so don't expect it to be as nice as this but i'm sure it'll get the job done i don't know if i went far enough down yet yes good now i'm gonna point this out real quick the way i have this set up now you guys could probably see that comment up there if you see something that doesn't seem quite right like if i were to continue to do this which i could and probably work fine on this is there something that i'm doing wrong i know there's a bit of delay by the time you see it and i record it but so what i'm basically going to point out is that if you look the way i have this thing set up the force pushing down on this pinion is going to be exposing exposed to this threaded bolt assembly the bolt is big but it's not really designed to carry the tonnage of force that i'm going to be putting on it so i don't want to have this bearing separator set up on my press like this i want to have it set up like this so really the only thing that the the bolts are doing is squeezing these two together and the press itself is the force is going through the pinion to the splitter halves and then to these little pads that they're sitting on also when you're using this press make sure that you zoom back out make sure you lower it down on these these little pins because if you take this up and down to change the height of these pins and you forget to lower it you're going to be putting on the force on these little cables and we've broken these cables before because of that so i'm going to push it down i want to get my hand underneath there to catch it okay so i got my bearing off and i got my pinion gear now if you look this is what we were trying to get to this is the shim the shim is thirty eight thousands and the reason why i know it's not because i'm feeling i don't have micrometer fingers but the um eyesight's not going as good there's actually on these gm's probably won't be able to see that too well but i'm trying to reflect the light into it right where i'm reflecting the light that has a 3 8 stamped on it it's kind of nice they stamped that for you 38 thousands all right i'll take this back i'll be back here in a second all right so now actually we've got everything 100 taken apart and i'm going to use these uh special tools to figure out what i do with them it's a box sitting somewhere there they are okay i didn't need to step away from the camera but this is a special tool kit and maybe i can move this boom over to show us what we're looking at on that i know this is going to be crooked looking and weird but i got everything kind of stacked up here these kits aren't cheap but going back i like kind of sharing this whole backyard mechanic idea with you guys because i do think this is something that you could do in the in your own garage if you're into this stuff this kit isn't something that you can go out and buy uh it's i think it's over a thousand dollars but you really don't need it if if you think of what most people are doing when they set up axles as they're going through and changing gear ratios putting a new differential case with a locker in it or something like that this kit right here is to set up a bare housing like we've got sitting over here and it's to figure out what size shim to start with basically and i have the students do this in our class just because you know this is part of the process and at a dealership they do have these tools the dealers i don't know if they use them too much but the dealers do have these tools to set them up and find out where what the shims are supposed to be and just like in the lectures i do mention when do you use the special tools it's when you're uncertain about the way it was set up in the past and it's also when the um when you're getting a new axle housing but you're keeping the gears or you know really if you're just getting a new housing you're going to need to do it anyway it gives you a starting point and what this uh you see i partially assembled this this is going to mimic a perfect ring gear center line if this sits in where the bearing of the differential case the side bearings go in and this is actually going to end up hitting the the pinion depth tool and then this is going to mimic a perfect drive pinion so i need to assemble this up i'll actually have to use that bearing that i pressed off so here's my bearing i need to find a spacer that fits in there perfectly uh oh i thought it checked all this apparently i didn't okay we're going to improvise in the other kit i didn't bring all the kits over in there on the other lab there's one that fits into this spot perfectly you know where those are at mike you know where the the um the table is in there that have that little green file full just like right inside the door there's a couple kits even that there's one that's just a tupperware he's gonna come back and get it so that way we can put together correctly and like i said we don't need these special tools the special tools are just one of those things that will basically tell us where to start you're almost always better off using the shim that it came with because like i said the axle housings are the part that are are variable in a sense and to talk about using these special tools and a lot of people think well okay when i get an axle and i overhaul it i'm going to need these special tools to do it not not true because even when you set an axle up from the very beginning i don't even use a ring in our opinion to set it up i use this tool to establish the ring gear center line and i use this tool to establish a pinion so when i get done the only thing i've used was a bearing in the axle housing and then the tool kit then when i'm done i get a reading but that reading doesn't have anything to do with the actual pinion itself all it did is look at the housing all it did is look at the housing and give you a number thank you sir and then this is the one i was looking for if you take a look it fits nicely inside this bearing so this is going to end up threading on here and then i'm going to have the basically the pinion if we want to call this the pinion this is going to simulate it and what this does now is it basically is going to hold that bearing centered hold that tool centered in there so that way when i go back together when i go in with this i have this pinion sitting in there just like it would be in an axle in the assembled unit and then this perfect ring gear center line is going to position itself on what this perfect pinion would be and um then i'm going to get a reading you'll see how that happens on this um this this one here actually has four different heights as you probably noticed and the reason why they do that is because this tool will work on four different oh one second there this tool will work on four different axles actually work on way more than that but it has the size listed and on this tulip here this is eight and seven eighths eight and a half eight and an eighth nine and three eighths there's actually this adapter here that works on the smaller ones it's a six and a half seven and five eight seven and a half so by the time i'm done with that mike you could change that bearing or that battery if you want it's low on that one but since this is an eight and a half i'm going to use this so basically like i said this is sitting in this axle housing like like its opinion a perfect drive pinion it's probably why these tools cost so much is because everything here has got to be pretty precise now i'm going to take my perfect ring gear center line and i'm going to position it in there since the pinion is offset to that side i like to put the part that's going to contact it offset to that side as well and i do need to put my bearing caps back on i don't need to like torque them down or anything like that just kind of snug them up figure out what to do with the bolts because just a little bit of debris underneath these little side bearing things that could hold it up lift it up a little bit stuff everywhere so are there any questions coming in there mike or is everything wow you guys must i must be doing a great job that's the only thing i can think of so if this was just a axle you're just changing out a diff case in to go from an open diff to a locker or something like that you wouldn't be doing this process you wouldn't be going through and using the special tools the only as i mentioned the only time you'll use these special tools is if you are uncertain about who set it up and you just can't trust that pinion shim that's in there at all if the thing had a relatively low mileage and it's already creating noise or if um you got a new axle housing oops oh shoot i forgot about that this has got the bigger bearings i don't know if this this one will work then i should have taken that into consideration all right so we might just get past this part um as i mentioned the tools have this this has to simulate a perfect ring gear center line and this is the one axle i've got probably should have grabbed a different one because the one axle i got that's got a little larger side side bearings than the others that i have and i don't know if i have the the parts that go with this kit i don't think i do actually i'll take a peek here in that kit there might be some bigger discs but you know because this side won't well that side won't fit in there it's just too it's meant for a bigger axle housing well let me try it i'm gonna see if this is a it's close but i don't i don't think so but we'll try it what's the worst thing to happen just actually i think that might be right i might just head on backwards we'll find out here in a second because if the the reading's going to have to be between basically 30 000 or so and 50 thousands because anything other than those two extremes they don't make pinion shims for um actually i think 25 thousandths is the smallest but in all these axes i've ever taken apart i've never seen one uh go below the 30s and i've never seen one go above the they're always in the 30s so and i guess that's worth looking at or knowing because if you're rebuilding one of these and you don't have the tools if you started it like say 35 thousands you'll probably be pretty close i've never experimented with that but okay yeah i think that'll work um looking down now i got the little pad that says eight and a half it's right underneath this little uh the ring gear the arbor assembly i have here so right now i need to put a dial indicator on this and this tool right here is the dial indicator that one's kind of sticky i'm gonna grab the one out the other kit okay so these things are actually not cheap so that's one of those that you just don't want to drop them i'm gonna put this on there so that way i'm squared up on it and make sure it rotates on the dial a little bit and then tighten it up not a position i normally put my hands in okay and so at this point i've got this dial is sitting on this pad you can see i got full motion out one of the things i see people mess up on every once in a while is they'll tighten this the dial indicator on and there'll be a gap between the dial indicator and this plunger you got to make sure there's no gap so i'm going to lift this tool basically i have to lift the plunger up and get it on that pad and you can see i'm going to rock it back and forth and the point you want to move you zero this out when the when the dial goes to the point of highest deflection so i'm going to zoom in on this and how do you know which of those four pads do you use if you look close the uh they actually have the the size of the axle stamped on it so i know i'm working on an eight and a half inch 10 volt gm and the eight and a half inch is referring to the diameter of the ring gear so i know it's an eight and a half inch gm so i'm on this pad that says eight and a half down there that's a good question though so now i got this plunger sitting on the pad i'm going to rotate it up to the point where it deflects the highest meaning i'm arcing this thing back and forth and when i get to the point where it's completely vertical that plunger plungers stuck up all the way and then one okay i'm going to zoom out because you can't see my hand motion there when this thing's uh when you're rotating that arbor this back and forth you're moving that plunger up to the point where it's vertical and then it's going to go back down and go the other direction goes vertical and goes back down so the highest deflection is when i move it from one position i see the needle climb and then it starts going back down when this thing is perfectly straight up from that arbor that little pad down there that's gonna be the point where the numbers gonna read the highest so at this point right now i'm at 56 but i don't really care about what number it's on because i'm going to zero it at that point so basically i'm zeroing it at the point of highest deflection zero then the down zero then down and then what i'm going to do is i'm just going to let it come off of that pad and the number that it reads on the dial is the shim that you need it almost seems like like a magic trick really if you look that says 39 thousands if you remember what shim was in it to begin with this guy it was 38 thousands let's see if i get the light to make it right there so it's actually pretty close um within a thousandths from what they were saying so this tool is kind of interesting it allows you to basically take the axle housing without opinion without a ring gear take a housing and figure out what size shipment needs so if you were if you had this like in a uh you were just stocking these or something building them for customers and you didn't necessarily know the application you could just write 39 thousands on this and know that whatever opinion you're going to end up putting in here that you're going to put a 39 000 shim in there to start with so and that's what we'll do we'll go ahead and find a 39 000 shim put it in there this right here it's a kit that we've got at school and i have a variety of shims in there so 39 is probably gonna be one of these there we go here's an example of something that's kind of odd that if you look somebody's gotten rough with this maybe the bearing separator hit it or something it's got a burr on it so whenever you use shims this is kind of generic overall oh it's almost common sense but people forget it all the time is if you put something in there it's got a big old fat burr on it it's not going to act like 39 000 shim anymore it's going to act like whatever thickness that was that part with the thickest part basically so if you're doing this for kind of the a customer and so forth which i assume you would you might want to have a file handy run it over the edges just to make sure you don't have a high spot because you don't want that 39 000 shim acting like a 44 000 shim or something like that so we'll put that in here in a second i'm going to take these tools out there any questions about the uh this pinion depth setup feel free to ask comment up so like if i was rebuilding my tahoe putting a 4 10 gear set in it or something like that because i put a big old supercharged ls engine or something like that i wouldn't mess with this because my tahoe it's got 300 000 miles on it and i can trust that it was set up right from the factory if i can go heck if you can go 100 000 miles on an axle without it making noise you could trust that it was set up right from the factory and i would just use the pinion shim that was in it even with the new gear if it's off it's only off a little bit and the tool wouldn't have helped you the tool would have probably told you to put whatever you had in it okay so i'm just stripping this thing down to the parts real quick and we're going to start going back together with it at this point we already know what our pinion um depth chin is so that's kind of our first step if you remember going back to our the steps of what we're supposed to be doing here that very first step is pinion depth seems like oh my gosh spent all this time and you only gone through one step remember we had to disassemble and we did some of the disassembly checks in the process so now we're actually going back together i'll grab my 39 000 shim i just deburred put it on the drive pinion and there's my bearing i am going to just pile this on with a pipe you could use a press but i'm not gonna now this one right here it says no hammer and then this is the side you hit because you'll end up burning these things over really bad and before you put that bearing on too probably a good idea to make sure your pipe will go all the way down like gosh that didn't go all the way down does it okay let's yeah a couple of questions here is it true that torsion style 10 volt differentials are inherent for making noise um well the torsion differential is is basically what's going on inside the differential case that goes on in here like this is the eaton locker so the torsion part is in here it's a set of worm gears that go in there it's there for limited slip so if you got an axle that's making noise going in a straight line it doesn't really matter if it's a torso or if it's a you know open or limited slip or anything like that or a locker if it's only making noise during turns then yeah then that torso i haven't really heard of problems with those so i don't think those are big issues but if you've got a noise that's going a straight line it's because of the ring and the pinion or the bearings and the biggest thing about noises the noise complaints that you hear about most are when people change gear ratios and they use aftermarket gears i'm not saying aftermarket gears are bad but not all gears are equal i don't want to say names or anything like that like there's a lot of aftermarket companies u.s gear yukon richmond and some of them are just noisier than others and it's probably due to the shape the way they've cut their teeth and there isn't necessarily a problem with that like so if it's set up properly and your contact pattern's good and it seems to be a little noisier than what was in it it's probably just the the gear set design oe if you if you take and you buy a an oe gear this is an american axle manufacturing so if you went and bought an am gear it's probably going to be as quiet as it was from day one from the factory but if you go out by an aftermarket one it might have a different sound to it but yeah so you'd have to diagnose the noise is it something that's happening only on curves if it is then it is something with the diff but torsions are usually really quiet they're really good gear sets and is it common to rebuild the inside of a differential case yes limited slip the question was is it common to rebuild the inside of a limited or a differential case if if you have an open differential case and we'll i'll show that tomorrow with the dana stuff because this is a locking mechanism here and it doesn't have the open style the um on an open type there are measurements that you're going to do basically to see if the gears are worn out if there's excessive clearance and the measurements might include basically putting a dial indicator on a side gear and moving it back and forth and seeing how much slop it is and comparing it to specs or more commonly they'll have you stuff a feeler gauge and see how much of a gap you have between the case and the gear because if they wear if the teeth wear out they'll establish more of a gap another area that's common for some differential cases to where is this pin this pinion shaft pin will elongate or egg shape the differential case and if that that happens this thing's popping back and forth every time you accelerate and decelerate and creates a clunking sound that's no good if you have an open differential and you get stuck on ice or you know you like doing one tire fire burnouts you might end up destroying these gears because these gears are really meant to an open differential these gears are really meant to just account for the differences in wheel speed when you're turning or when one wheel goes over a bump and the other one will the other wheel doesn't so it's not meant to basically run together like you would see a ring and opinion if you think like if you got caught on ice and you probably have noticed this like i got one tire spin like crazy and you saw your speedometer go up to 60 miles an hour there's a good chance that one wheel was going 120 miles an hour and the other wheel was going zero so if you imagine what was going on in this gear set here these gears are sitting there spinning like crazy and you've got a lot of there's no bearings around them or anything like that it's just a steel gear around a steel pin so it's really bad for it so yeah that's what you'll want to inspect when you take it apart if you have a limited slip differential the limited slip clutches can wear out over time and the way you check those and there's a separate lecture on that that i have that's on limited and locking differentials but you would basically hold one wheel stationary with either keeping it on the ground or whatever or putting wheel chocks underneath it having the vehicle in neutral and then on the other wheel try to rotate it it's not going to want to rotate because the limited slip clutch packs in there are grabbing they've got preload on them so it's going to take a certain amount of torque to actually force that wheel to spin and i'll show you guys this stuff later but the the amount of force it takes for the wheel to spin is the breakaway torque it should be like 40 50 foot-pounds or more and that's the number i threw out there but it's going to take quite a bit of torque on that wheel that's up in the air while one wheel is stationary on the ground and the vehicle is in park and neutral to break that torque away and if it's easy to break away the clutches are worn out and you replace those so you rebuild them now in this assembly here this is that eaton locker i keep talking about and the eaton locker is kind of a fancy set up here it goes in on a lot of gm trucks there's a lot of gm truck owners that have it and they probably don't even realize it and it's a locking mechanism that when one wheel goes a different speed than the other wheel by a couple hundred rpm these little governor weights fling out they'll grab on to this device called the latching bracket and it and when it does that it there's a cam in here and it causes these these uh clutch packs that hyper compress if you will on each side and it locks the side gears to the differential case once again this is on a another lecture so i'm just kind of trying to answer the question these things if they're worn out you have to go back with new clutches and this plate or this plug if you will this uh the assembly here in the middle that is selective and it comes in a bunch of different sizes and you actually need a special tool to go through and measure what size you need if you don't get the right size in there this thing won't work at least it won't work properly so yeah it is common to rebuild these things and um we're kind of skipping through that just dealing with the ring and pinion but yeah you would definitely want to um deal with that stiff case and the same goes true with this ring gear if i take this ring gear off i take these bolts out these ring gear bolts they're not reusable so i have to go back with new ones the reason why is because these ring gear bolts aren't actually that big they're probably 3 8 inch you know studs there and when i torque these down they might be 60 70 foot-pounds of torque so that's a lot of force on a small bolt and it stretches the threads it kind of deforms the threads a little bit if i try to go back especially i might get lucky i might be able to tighten it up one more time but if i tried to do it twice i'll probably rip the threads off and it won't be useful so you're supposed to replace these ringer bolts every time you take them off if you take these ring gear bolts off this gear won't just fall off there it will there's a press fit i'll have to use a brass drift and tap it off which also means that when i go back together with a new gear it's not just going to fall onto the differential case what i do is i've got a little cookie oven and i heat it up to 200 degrees that's the temperature that it can live in and the vehicle finds so it's not going to hurt anything and let it sit in there for uh 20-25 minutes until it's golden brown on each side that's a joke but 20 minutes or so and use some welding gloves drop it down on there and get ready because once it cools off it's going to squeeze onto it because it'll drop on there well that heat will expand this gear enough to let just fall right on get a couple bolts ready start them you don't have to tighten them just get them started and then once you know everything cools off you can go through and tighten them all up and when you tighten them you want to do them in a sequence you don't want to just start turning tightening this and go all the way around you want to do it in in steps like maybe tighten it 20 foot pounds first do it in a star pattern you know i'll take a paint pen and i'll mark it with one dot when i tighten one and that's the first step and then i'll make sure all of them have a dot on it and they've kind of gone random and then i'll tighten it to the second maybe 50 foot pounds and then i'll tighten it to its final torque and so by the time i'm done everyone will have three paint pen dots and it'll be torqued down to the right torque you want to do that because if you don't follow the steps in a sequence you're going to potentially distort the case and also distort the ring gear that makes sense hopefully all right so i'm going to pound this bearing on now you guys say a little prayer for me here because this i think is burnt over a little bit i i tested this by sliding this down and you can see it goes down most of the way but not all the way so what could happen that's bad and i've had this happen as you start pounding this thing down and then when you're done this thing's the pipe stuck on it in it and it's uh now this is good yeah well this side i actually had at one time i had to machine the inside of this out to make sure it fit around this that's why i put no hammer on this side because this is the side that should fit you know um but it's already burnt over a little bit now see if you can i know it's probably the the microphones hate this sound but um if it's coming through you might hear a noticeable ping sound difference when this thing's bottom out it's going to get a higher pitch it'll be a lower pitch sound we'll see if you can hear it [Music] so right there those last those last three hits i had were lower pitched and it came right off no problem so the prayer worked but uh so here's my my bearing and my shim in there i was i usually try to look at that real close to make sure that there's no gap i've seen it where people thought they pounded the bearing in all the way but the the maybe the pipe or something hit a ledge and it didn't actually go down all the way a little bit of oil on these gears are important because this is we're not on our second step we got our pinion depth set in there and now we're going for pinion preload so we're going to go back with our our bearing our front bearing these will all be new bearings and i'm going to want to have a coating of oil on it and in fact i'm going to spin this axle housing around so this is where some people will be like all right i can't reuse this collapsible spacer i'm not supposed to this is a a one-time deal but if you are really confident that this is going to set up and the gear contact's going to be good go ahead and go in with your new collapsible spacer if you are dealing with a you know a nightmare of an axle something that just wasn't set up right maybe and um you just don't trust it and you don't even trust the the shim that you put in is actually going to be the right one you might want to reuse your old shim or your old spacer but expect you know when you're done you have to have a new spacer in there so you might go through the setup as if you're going to have to take it apart and change it again just for the sake of [Music] of making sure you're not wasting parts all right so i'm going to put my spacer on the same actually holds true with the the seal if you don't think that if you think you might have to take this apart because it might not be set up quite right you probably don't want to put the seal on until you know for sure now i can see just a couple threads that's not quite enough so if i can't i'm just tapping this down [Music] so that way i'm getting the some threads exposed there so hopefully that makes sense though what i was trying to say is like if you don't have confidence in what your pinion depth is how it's set up you might want to reuse the spacer and not put the seal in in case you have to take it apart again but when you're done and you've got a good contact pattern everything looks great just take it back apart put it put your new spacer in your new sealant and put it back together exactly the way you took it apart and you'll be fine so at this point right now i've i've got my my my pinion in there with the proper shim the collapsible spacer in there i just reused this one because you know we're not putting new ones in every time and also you put a new pinion nut of course reuse your old one if you don't know if you're got a good setup and then i'm going to tighten this down now this is where i you know some this is where sometimes students get confused it's like how tight do i make this and if you remember what i was saying earlier since this uses a collapsible spacer you're not going to find a torque spec in the service manual for this you're basically basically going to be tightening this down until you can get the right turning preload on it so because what i'm doing in this process now my spacer that's in there has already been crushed as you know because i reused it but when i tighten this thing down i'm going to be tightening this down until i can get the proper rotating torque and what's the rotating torque well that's our pinion preload that's step two so step one was our pinion depth we got a 39 000 shim in there according to what the tool said and then step number two is pinion preload and that's what we're doing now if this is set up like it's going in a vehicle i would have a new collapsible spacer in there and have the sealant everything would be oiled matter of fact one thing that i even mentioned is i even put sealant like pipe sealant on the splines because you don't want oil leaks to travel through the splines and out through the nut because those aren't going to be perfect seals so i'm going to tighten that down and normally this would be over 200 foot-pounds but because i'm reusing the collapsible spacer i'm basically just bringing it back to where it was already crushed and for the preload is pretty close to being right on so i'm at that point now where i've got to do a preload check these bearings are kind of rough i'm getting about 20 thousandths 20 inch pounds not thousands 20 inch pounds this is why it's important to have oil on these bearings and you have to kind of look at it as it's spinning around it's not the breakaway torque it's not the amount of torque that it takes for you to initially start rotating it if you look that's really high that's like 45. once i get it spinning i'm looking at the dial and i'm trying to see what it kind of averages out at whoa this is a tool that you will definitely need so if you're a little backyard mechanic whatever you will definitely need to have a torque wrench because the preload isn't something you want to guess on if you remember the purpose of this preload is to put the clamp on this bearings is to keep this pinion from from moving around if this preload is loose this pinion well it might spin real easy that's like best case scenario but if it's really loose this pinion could move around and the way i like to explain this preload is like it's like squeezing something together it's less likely going to move right if i just hold on to something it's going to move around it's go you can deflect it the tighter i squeeze something the less likely it's going to be to move and deflect but if i squeeze these bearings too tight i'll overheat them and they'll fail so that's the reason why the preload is something that you need to look at the specs and find out what they want you to have it set at and on this axle here they'll always give you a new and a used spec and i see him measuring it right there sidebar okay i think it was probably on the previous page all right this one here says preload should be 20 to 25 inch pounds on new bearings and 10 to 15 for used so if you're reusing the bearings the reason why they're a little lower is because they've already kind of set in they've already established their little wear pattern so right now i'm 20 20 inch pounds i'm going to remember that so i think my pinion is set at the right preload and it's at the right depth now i'm at the point where i need to get my axle and drop the ring gear and the diff case in there and set up the backlash and the side bearing preload if you remember my little list here this is step three you guys see that we've done pin we've already finished pinion depth we've already finished pinion preload put little grease marks on there and now step three is kind of a combined step side bearing preload and backlash so this is where i take my diff case i gotta do this carefully because i don't wanna lose a finger again mike you got your suture kit just in case i hope all right so i'm going to drop this in no shims or anything at this point i'm just putting my bearings and my diff case in there if you remember early on in this presentation towards the beginning i mentioned that when you normally go back together with these you would use this service spacer and then you would use service shims but because this axle has little larger bearings i can't use the service spacers that i have available so what we're doing is we're improvising by using some of these shims here i do have the larger shims but i don't have any larger service spacers and um if i take a 260s and a 50 that's 170 thousands which is pretty much the same size as the the um service spacer that i would normally be putting in so if i put this in start with kind of drop that in actually the 50 i have is a smaller one but if i sandwich it between the two it will still work okay then the other side how do i know they're 60 well these are marked with 60. so ever mark them i hope they're they're right um here's another 60 and i can't see now obviously if you don't have a marking on it you don't know what it is you're gonna have to measure it that's 50. okay so 170 thousands on each side this is if you're doing this in the backyard or if you're doing this at a dealership this is one of the ways that you can do it it's very important that we get backlash set up properly and the clamp that's on these bearings set properly if i don't if i have my my preload these you know the same same thing with the pinion how we had to clamp those bearings down put the right amount of preload on it i have to do the same thing with the side bearings if i don't have the proper preload if it's too low i can cause deflection of the deer gear case or the diff case here so that can cause the ringer to move in and out would that be bad or it could also if i have it too high it can overheat and wear my side bearings prematurely so it's very important that i need to know what my side bearing preload is and if it's accurate if it's within acceptable range also the backlash the amount of clearance that i have is very important this thing's designed to run if you remember i think it said five to nine thousands backlash if i ran it too loose it would possibly be clunky but also it would run the pattern off the heel and i would end up having a gear noise if i run it too tight when this thing heats up it's going to lose its clearance and i'm not going to have room for oil and i'll overheat the gears so this process here is what's called the shim method if you bought an aftermarket gear in an install kit you're going to have some kind of a mechanism or some kind of a sandwich design usually they have two shims with a a bunch of thin shims that go between it you just basically have to take them in and out and experiment with it but right now what i'm going to do is i'm going to put what we call a bent 40 thousandths on this side this is the i like to call this the pinion side because the pinion is offset to this side because the pinion's got you got to make room in this axle housing for this pinion so the ring gear is all set to that side the pinion is offset to that side the reason why i don't like to say right left and all that is because depending on how you mount these things on there if i had this 180 round i my right and left would get mixed up so if i'm looking at this if i so call this the ring side always and this the pinion side then i could just use those terms but i put a purposefully bent shim and i use a 40 000 shim because it's the smallest one and it's going to work like a spring and i might actually and i'm going to go ahead and do this i might have to pull one of the normal shims out because sometimes i just need that extra clearance but um not trying to confuse you guys on the steps here at all but the purpose of the bent 40 thousands shim is the work like a spring so that way because what i'm going to start doing is i'm going to start filling up the ring gear side shims until i basically have no no backlash and then i'm going to pull my bent 40 thousandths out and i'm going to fill up the pinion side of the diff case until i can't get those shims in anymore the whole idea here is it's a little sequence to figure out how much shim do i need to fill from each side of this uh on each side of this diff case i'm gonna take up all the clearance and then when i figure out what shim combination i have on each side i'm going to make an adjustment for backlash and then i'm going to add some for preload you'll see here in a second so right now i've got 170 thousands of shims on the ring gear side and i have about a hundred twenty thousands of shim plus a bent forty on my pinion side so i'm gonna start filling my ring gear side first because i'm gonna wanna take that backlash out let me use a screwdriver to kind of pry it open give me a little space and this is kind of a um go by feel method here i just grabbed a 66 thousandths i'll double check that in a second and i slid that in there you know you probably can't hear it but still got a little bit of backlash and what made me start with the 66 thousands well when i stuck my um when i stuck my screwdriver in there that was about the thickness of the gap i saw and otherwise i would just be experimenting i would just grab a shim i'll switch over to the boom view here so you can see it and okay so yeah i'm basically just filling this gap i put the 66 in there i'll verify that it was 66 and that says 64. it's close enough and then maybe go a little larger now i'll go to 68. because i was really close with that this is 66 maybe um and then also here's a burr on this one so i want to make sure i'm not using one that's going to act like a larger shim how these things get burrs on them is the students end up using a hammer to pound them in as opposed to using a driver and so you got to be aware of that because you don't want your tools to screw you up okay i slid that one in still just a tad i'm gonna go maybe to a 70. you might not get like you might just have a thousandths or so backlash that's fine but you don't want it to be bobbling back and forth real loose all right so we'll see what this does all right that's good i think that's probably the right size shim so right now i've taken out all the clearance that lives on this side because i don't have any backlash in my gear anymore so i'm going to do over here on the pinion side is i'm going to go back in with my shims and i'm just going to fill this up pretty much stuff whatever shims i can in here until i can't push them in by my my hands anymore make sure i got the right ones start with my 170 thousands and then i usually start pretty low like 40 000 or so and work my way up this is a 40 000 shim this might actually be the one we need to start with because it's yeah it's that's tight going in so that's the smallest shim i got and i can't be like probably i could jam it in there but i'm going to leave it at this this is a 40 000 shim and that's all that'll fit in there so i have a 70 000 shim on this side and a 40 000 shim on this side and in order to now because but basically with the 107 i'm going to write this down on this table here i think so that way we can we can kind of keep this math straight because what i have is my service spacer is 170 000 so i've got that that's that combination of two 60s and a 50. so i have 170 thousands on each side and then on this side i have 40 thousands so for a total of 210 thousandths on this side so far on this side i put a 70 if i think remember correctly so that'd be 240 000 but at this point i have an axle that has no backlash and pretty much no preload because i've been able to fit these things in by hand pretend that pushed in all the way by hand so if i want to get backlash i need to take six thousands out of this side because i'm gonna shoot for six thousands backlash i'm gonna take six thousandths out of this side and put it on that side so i'm going to transfer six so subtract six thousandths and i'll add six that should move this ring gear away from the pinion right not getting all my hand action in there so this should move the ring gear away from the pinion now that would give me my backlash but wouldn't give me my preload so i'd have to add four thousandths to each side and where am i coming up with these numbers the four thousands so each side is pretty generic it's saying like any axle you work on if you take all the gap up in this uh between the bearings and the housing and you add four thousands to each side you'll pretty much get the right preload and where am i getting six thousandths the minus six plus six it's usually about a one to one relationship if i take a thousands out from this side and put it on that side it usually moves the gear over a thousandths of an inch or six out of this side six out of that side it should give me six thousands backlash so all these other numbers right here these numbers right here are based on the axle the plus 10 overall that that occurs on this side the plus ten thousands let me erase i just made a mess there uh the plus ten thousands on this side and then the minus two thousands on this side that is what we do once we get these numbers figured out that's what we do to these numbers to get our side bearing preload in our backlash so going back to this um i should have written all over that 210 210 plus 10 and then 240 minus 2. which is basically i'll be putting a 68 000 shim on this side because i already have the 170 in there and i'll be putting a 50 000 or so on this side keep putting forgetting to put the zero there because i had a 40 in there to begin with all right hopefully i didn't confuse you guys too much but let's see how this works the dana method uh dana's the system that we'll do tomorrow it's a little simpler than this probably good they do use special tools though for better for worse so basically i took uh took out no i took the wrong last one a second that would have been bad i took the 50 000's out use a little screwdriver to kind of spin these out of there i'll verify that i took the right one out yeah i'm gonna put a 68 in hopefully if this thing all sets up right i'll end up with the right amount of preload and the right amount of backlash on the first shot what are the chances a little low on small shims we'll see how this works this shim right here that i'm putting in if i could put it in by hand i know i didn't set i know my measurements are not right because i should have to pound this shim in because it is i've got an axle that needs to have side bearing preload so this should not be able to just push in all the way by hand i'll need to get my hammer and tap that in now i've got they do have tools to do that with this one right here is a side bearing shim installer kent moore sells it you'll see some people will go through and just hit these with a hammer but remember that causes those burrs these uh i don't know if you guys know chris reynolds he teaches at lewis and clark community college he had his brother make these for me but kent moore does sell them see i have to tap this in since i have to tap that in i know i'm adding preload and i added backlash i don't want to check my backlash yet although it does feel kind of high i don't want to check it yet because um it might not be sitting all the way down so i want to tighten the bearing caps up a little bit so there's two things i need to check once i have these shims in here even if that backlash was a little high that doesn't mean all is lost because if my preload is good that shows me that all i need to do is do a little side to side adjustment on my shims and even if my backlash was good that doesn't mean i'm i'm definitely good and done because i need to go through and check my preload so there's two things that that this these steps accomplished here one was setting up preload and the side bearing preload and the other one was setting up backlash and if i um if one's hopefully they're both good but if one's off the other is on you just have to adjust for the one that's off if they're both off then it's you gotta know it's kind of a guessing game you have to make a educated guess okay so i snug these up very first thing i'm going to do is i'm going to go ahead and do my backlash check remember the spec on this was five to nine thousandths of an inch i'm getting 13 there so i'm over third 13 looks oh no yeah that was 13 12 or 13. what would be the customer concerns with too much or too little backlash so the question was what would be the customer concern with too much or too little backlash well if i let it go with this with too much backlash the axle would probably have a gear wind because that contact pattern would be coming off the heel and so i wouldn't want to let it go this way so i wouldn't even bother i mentioned this in our videos or lectures there's no point in doing a contact pattern yet because the backlash is off so i need to make an adjustment for backlash um i'm at about 12 000 so i'm off i'm going to before i make any adjustment i'm going to spin this around and i'm just going to measure my preload because if my preload is good then i know all i have to do is take whatever thousands of shim i have on one side and transfer it to the other but if my preload is off then i need to maybe add a little bit more or subtract some from one of the sides as well so let me just check that real quick and so i'm getting about 25 inch pounds of preload and those of you guys we've recently went through this lecture how do you figure out what good side bearing preload is well there is an equation i'm not going to go through all that with us right now but the side bearing preload is the side bearing as the total preload which i just measured at 25 race this my total preload that's everything was 25 inch pounds if i subtract my pinion preload which if you remember was 20 inch pounds the difference is 5. that doesn't mean my side bearings have 5 inch pounds of preload it means that at measured at the drive pinion my side bearings are showing five inch pounds difference but if you remember it's going through this gear reduction so if i go look at my gear reduction i've got 12 and a 41. is that a 342 there's 12 pinion gear teeth and there's a 41 ring gear teeth i i told you guys i was good at math and here i am doing this uh divide 342 so this is a 342 gear set so i'd want to take that five inch pounds of torque that extra torque that it takes to spin the total unit versus the pinion by itself and multiply it by 3.41 or 42 in which case that would be 17 inch pounds so the that's 17 inch pounds is the preload that i have on these side bearings it's actually not that bad if you think of the pinion used bearings could be 10 to 15 use new bearings 20 to 25 used 10 to 15. generically we say that between 15 and 35 is what our side bearing preload should be and we're at the low end of that so if i want to increa decrease my backlash so i need to remove shims from this side and add them to this side i could remove say six thousandths from this side and then add maybe eight thousands to that side and that'll give me a little bit more preload if i wanted it and a little bit more or reduce the backlash do that real quick see this this is the type of stuff there's the reason why you need to kind of go through a process now usually when i demonstrate this in class it works out perfect but because i'm doing this on the internet of course it's going to fight me a little bit and um make me redo this part but we're not that far off so this is the trial and error and if you don't have the shim kits like i'm showing here which if you've got an install kit from randy's worldwide or summit racing or something like that you're not going to have this huge assortment of shims what you're going to have is like i said a sandwich pack if you will where this shim is basically made up of two shims with a bunch of thin shims that you put in between so you're going to have to write down sizes put it together measure it and kind of tweak it accordingly all right my three quarter inch wrench one there it is remember spin the axle housing out let's see how you do by hand now yep sometimes you can spin them out by hand once you get one shim out they're all loose see if i can do without hurting myself okay so go back in with my on this one i'm going to add eight thousands to um or wait i don't want to add on this side i think i did the math wrong i said add that would give me more so i want to transfer shims from this side to that so i had a 50. let me let me double check my shims see that was a trick i was seeing if you guys would catch that you didn't so this is the one that i put in that was like a 56 there's a 50 60 and a six one second 52 50 60 and a 60 okay 60 i got to make sure i get my my 170 000 set up in there the way that was uh um my basic of the equivalent of my service shims and then on this side i should have had like a 68 thousandths i think right is that sound right 66 68. okay so that one was the shim these are the shims that were in there i want to get this ring gear closer to the pinion to reduce the backlash so i'll have to go smaller on this one by six thousands so if i had 50 to start with i'm going to go ahead and put a 44 in there going over to my shim selection here trying to find a 44 i do have a variety of them that's what's nice and then i'll put that in like i said the movement that we're trying to do here is we're trying to accomplish reducing our backlash primarily and then maybe increasing our preload a little bit and then this one's 64. so that six thousandths i took off of this side i'm gonna have to put on this side to move that ring gear over and keep my preload the same but if i actually instead of putting a 64 which was in it i could put i have to put the 70 000 so i might go 72. that'll give me a little bit more preload too these things aren't in the right drawer figure it's nice having this assortment of shims but man they kind of make for a little bit of a mess at times you get them laying out all right so once again this will have to be pounded in because the preload is going to require that it won't go in easily by hand and there's my driver tap this in put my bearing caps back on still feels a little loose to me but we'll see what happens if i can get it with inspect then we'll do a contact pattern and see what shows contact pattern is the tell all it's the thing that if you don't have the contact pattern set right then you will have an issue all these steps that we're doing ahead of time they're really there just to make sure that we're as close as possible and then once we're at that point we do the contact pattern our preloads are kind of set in stone we we're supposed to have the right amount of squeeze on those bearings and that but the backlash that feels a little better let's see what we got the backlash and the preloads are things are going to be set in stone there but this contact pattern is going to tell us if we have the pinion in the right position try to get this to stop moving on me eight thousandths so it is within spec i i usually shoot for the low end of the spec but we're we'll we'll take it so just for the sake of finishing this that's seven thousandths seven seven and a half if you remember why i checked this in a bunch of different spots is because if this gear is warped maybe because i didn't tighten it properly or whatever or it's mismanufactured or something's no good that backlash is going to change it's going to it's supposed to be maximum of 2 000 difference in any any spot so i don't want to just check it once but i want to check in multiple spots so right there my backlash is good it's seven to eight thousandths we're going to run with that i'm going to spin this around and just double check my preload if you notice i didn't get carried away torquing anything down really tight or anything like that at this point i'm just trying to go through and get this thing set up and then when i'm done i would go through and put the torque on the side bearing caps and so forth yep the side bearing preload is still at 25 inch pounds i expect to go a little bit higher but it didn't that's okay it's still within spec if you remember in the lecture we said that if you don't do the side bearing equation that if you measure your pinion by itself whatever you got 15 20 25 inch pounds that and then when you did the total assembly you should be five to eight inch pounds higher than the pinion by itself at that point you know you're good now we have to do a contact pattern i'm gonna paint different teeth this time because i already painted those three the before and we're not going to see too much of a change maybe the back of the the pattern will move more towards the center because we have less backlash and the way it was set up that's our desired result in class a lot of times i'll tell the students that purposefully screw up the pattern but since the backlash was off we figured that one was kind of a good one to look at when we started and then with this uh the backlash now kind of back within spec we'll be able to see if really the only thing we changed we changed the one thousandths worth of pinion shim but for the most part it was just backlash that we changed okay so remember i gotta do this without popping a tooth out i gotta go back and forth and then i'm gonna use my ratchet here to provide resistance all right i don't think i'm on my gear hold on the disadvantage of painting only a few teeth is if you're doing this and you're not over the teeth you're not going to see any if you paint more teeth you will see it all right the socket doesn't like to fit on my opinion up very well that's why it's slipping off that's my excuse okay i'm going to reverse my ratchet because i don't know if i was on the co side or the dry side i am on the drive side now yeah i believe let's see if i got it i might have missed it but we'll take a peek here oh yeah so this pattern looks a lot better than the previous one because let's see if i can get a good angle on it okay so if you look you can definitely see the for one the pattern is right here hopefully you can see that okay it's not running off the heel anymore you can still see paint there it's not offset towards the face or towards the flank if i were to reduce this backlash um you know it's an eighth out seven or eight thousands if i were to take it lower to maybe five or six thousandths it'd be a little bit more offset towards the toe but it is matching all the rules of a good contact pattern where we want the it to spend just as much time on the face as it does the flank it's over half the length of the tooth it doesn't run off the tooth in any direction and it is it's kind of centered but if it was offset towards the toe it would make it even better now if you notice i usually don't spend time looking at the coast side too much the co-side of this pattern does still look pretty good though actually it looks great it's right there centered if i go back to the old pattern and see if it still shows the co-side of the old pattern actually doesn't look that bad got a glare on that one so the coast side of the of the old pattern actually doesn't look that bad but if you remember the drive side is uh was running off the heel back here you can see i actually wiped the paint right off the heel so backlash moved the pattern from the heel to the middle and if i kept decreasing backlash even more it offset towards the toe which would be perfect but this axle would for sure run and it would be quiet it wouldn't have much noise so all told it it would be a good axle to put in a vehicle and so that was a setup of this gm axle we used the special tools we used that thing called the shim method there where you're basically doing shim swaps i know there's a lot the overall the the concept is the details are simple pinion depth pinion preload side bearing purl and backlash it's all the mini steps that go on under each one that adds complexity to it remember things in generic terms though so that way when you're when you're trying to figure this out one of the things i see students mix up is they think pinion preload is going to affect contact pattern or they they think side bearing preload is going to affect contact pattern the only way those would affect contact pattern is if these parts are sloppy loose and they're moving around in there but if i have pinion preload at five inch pounds or a hundred inch pounds the pinion's still in the same spot and it's going to create the same pattern if i had side bearing preload at five inch pounds or a hundred inch pounds this diff case is still going to be in the same spot because it's sharing that load evenly on each side so it's still going to put that ring gear in the same spot so my pattern doesn't change because of preload the only way the pattern would change is if these parts were so loose that they're physically moving around in there and that that's kind of beyond the scope of what we're talking about when i say how compinion or what affects a contact pattern the position of these gears are determined by the shim combinations on i have on either side of this side gear of this diff case and the pinion depth shim the one that lives underneath the head of the pinion um now when we were doing this whole math and all this uh setup regarding the side bearing i know there's a lot of shim swapping and all that stuff but the general premises is when i go together with it i'm filling this side up with shims until i got no backlash that i'm filling this side up with shims until i can't fit them in there anymore at that point i'd have an axle that's completely filled with shims with no backlash and no preload then i would take six thousandths out of this side and move it to the pinion side and that would move my ring gear away from the pinion and that gave me my six thousandths backlash and then i would take whatever i had in there now i'd have four thousands to each side and that would squeeze on those bearings and give me my preload so yes that's the general concept now me flipping shims and sticking screwdrivers in there and doing all that kind of stuff that was just what i had to do to get those in there and even this like i don't have the proper service spacer and all that kind of stuff this was the wrong size so i ended up using three shims instead of one of these do you think it really matters i mean look at it is it going to go anywhere the shims are in there and they filled up the space they're contacting the housing and they're contacting the bearing did work perfectly fine it also if i did this math and i figured out i had a 246 000 shim on this side and i had a cast iron one that was that same size and i wanted to keep my shims and put this in the customer vehicle by all means do it now like i said you read in the service manual and say do not reuse these but let's get realistic this is just a piece of metal and you push that thing in there it's going to live in there it's not going to go anywhere these little ears that they have on these bearing caps they keep anything from coming out the axle shaft goes through the middle so there's literally it can't go anywhere so um i don't know why they say that i would not be afraid to reuse these even if it was cracked as long as it goes in there and you don't break it in the process it's not going to go anywhere once it's in there so um i don't want you know this there's a lot of complication in the details but the overall process i think is relatively generic and so try to focus on the concept is probably more so than the details are there any questions up there mike that you can see just if we're going to post this up to make the video available and have we thought about maybe trying zoom to try this as well soon yeah um zoom might work but they have a time limit now so i was worried about how long did this take so far two hours and it took two hours to do this so i know zoom has i think a 40 minute time limit unless you have the pro version which we don't have the university i think gave out all their pro versions already so that that is possible to do zoom the other reason why i wanted to do it on facebook is because there were other schools that might want to watch us and i know i could like still share the zoom link though that that's still something that could be shared to anybody so yeah i mean really there's no reason why as long as i got a pro version of zoom that's why i didn't want to use the d2l classroom either because it would just be stuck to inside this class but yeah if we can get the pro version then i could do this the one for tomorrow and the ones next week i could do that on zoom and then we could also record those and then put them up on facebook and then uh youtube for anybody else so anyway yeah that's good comment good good um suggestion anything else that's all i'm seeing all right well if you guys have questions you can email me jeepster siu.edu um join us tomorrow join us tomorrow 10 a.m we're gonna go through a dana the dana axel uses different tools some of the concepts are gonna be the same so it'll probably go a little quicker um i won't have all these shims laying around they're a little bit less they're more tool intensive but less pieces and parts intensive and yes tomorrow 10 am dana axel be there just email me or post up a question if you have one

Channel: siu automotive

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Id: AsiRYnWcCQg

Length: 121min 0sec (7260 seconds)

Published: Thu Apr 02 2020

Reddit Comments

[u/banditorama]

Wow, small world. That's one of my old professors