Vibrations Part 3 Driveline angles

hey guys welcome back to the channel i just wanted to make a quick video on driveline angles because i'm still suffering from a bit of a vibration even though last year i did find a bent axle in this wheel right here and that definitely helped once i replaced that but i still have a vibration so we're going to look at our driveline angles because that's one of the most common sources for drive line vibrations now a lot of people out there are going to talk about you know the transmission angle and also the pinion angle and in a lot of ways it does not matter what matters is your operating angle here and your operating angle here now in an ideal world you want those to be equal and opposite to each other so say we have an inverted v angle here at two degrees and a v angle of two degrees right here we are equal and opposite to each other and therefore we are perfect now if you have a 70 to 72 chevelle with a t56 magnum and a 1350 u joint on a three and a half inch drive shaft you're probably going to run into the same problem i did where there is a huge clearance issue right here against the floorboard this cross bracing right here and i have banged the crap out of that and there is just not much clearance at all now that has forced me to run the transmission lower than i would like which also forces me to run a v angle at our u joint right here which is not really what we want ideally we want to run a inverted angle at our u-joint right here so i was running about a 0.6 0.7 v angle right here at this u-joint and i was running about a 1.7 degree v angle at this u-joint so the the angles were the same orientation and they were not parallel so they were not the same which might account for my vibration now unfortunately i cannot run an inverted v angle at this u-joint which means my pinion facing up because the coilover the way the bracket is it actually causes the spring to contact my drive uh my differential housing and brake line which obviously i can't have that so in my case i have to run a v angle at this u joint right here which means my pinion has to be somewhat downwards so what i've done is added a third quarter inch spacer which gives me three quarters of an inch raised jacking the transmission up which now does give me an inverted v operating angle right here at this u-joint but it does mean i am incredibly close in my uh clearances to the floorboard which means i probably will hit it when i hit a bump because this crossmember does flex a bit but you know we'll test it out and see how that goes now using the tremec app i can put this on the flat surface of my transmission yoke and it looks like i am about a two degree angle right here about 2.9 degrees on the drive shaft and about 1.3 1.4 degrees at the pinion which means i'm going to have to raise my pinion up because this u-joint angle right here is a little bit different than the transmission one so my transmission was i think was two degrees down so i want this to be the same two degrees so that's coming up which is going to be easy because i have adjustable upper control arms which i highly recommend buying if you plan on lowering or changing the ride height of your car so i made my adjustments and we're now at about 1.9 degrees the drive shaft is still at about 2.8 degrees which is great i've already checked the transmission which is at about 2 degrees so that gives us equal and opposite angles so we're going to button this up and go for a drive so just a quick overview of our driveline angles our transmission is 2.0 degrees down our drive shaft is 2.8 degrees down and our pinion is 1.9 degrees down giving us operating angles of 0.8 degrees at our transmission u-joint and 0.9 degrees at our pinion u-joint and that gives a difference of just 0.1 degrees meaning we are basically equal and opposite and nearly perfect so i had for a quick drive earlier just to make sure everything was staying together and not falling apart so far so good got up to about 50 miles an hour and no vibrations there but that doesn't really tell me anything since it didn't really vibrate at that point anyways hit a few bumps drive shaft has not hit the floor yet so that's good but the real test is to see what it's like on the highway which is what we're doing right now so driving along right now it feels pretty good very little vibration in the shifter which i'm happy about so i'd say right now at this speed which is about a little over 100 kilometers an hour feels good that being like 60 70 miles an hour is what we're gonna be going for here one thing i used to notice was that it would vibrate and make all kinds of noises under d cell so i'll speed up a bit and then i'll let off the throttle and see what happens well it doesn't feel like a vibration but there are some flinks and planks and noises and whatnot it sounds like it's coming from the rear [Music] well something's still making all kinds of rattles i'd say the driveline feels okay but man when i d sell for about 113 it creates all sorts of bunks and stuff so i feel like the vibrations on the highway have been reduced thanks to our new driveline angles and getting that a little bit better but there definitely is that sound in the back of the car which i'm guessing maybe it's the rear end when it's on d cell at a certain speed i don't know what that is so i'm gonna have to investigate that maybe i'll pull the diff cover off or something just to see what's going on but uh the troubleshooting on this car continues like always so i pulled the diff cover just to make sure nothing came loose or nothing was broken uh these main cap bolts 75 foot-pounds they were perfectly fine these bolts though were a little bit loose despite having lock washers and loctite on them 45 foot pounds i was able to move the torque wrench on every single one of those bolts which is a little bit of a concern i don't think it's enough to cause a vibration or any noise but you know something to look at if you have your diff cover off also i don't know if you can see this but look how much i can move the wheel before getting movement in the ring and pinion and that's just the free play in the true track differential and if i go hard that's quite loud right and this has always been like this but i don't know maybe it's getting worse is that the source of the noise is that normal i don't know i called true tracker you know detroit and they were like oh that's perfectly normal but that it just seems quite noisy to me but anyways everything checks out in here from what i can look at so i am gonna put the cover back on and fill it up with different fluid this time so the diff fluid we're gonna be using is the lucas oil 85 w140 we were using the 80w 90 and it pains me to go to the heavier 140 weight because i'm sure we're going to lose a couple of horsepower but we have to try something different right and because i'm using a true track differential we are not going to be adding any additive to this just the straight fluid while it didn't film it i did go for a drive with the new thicker gear oil and it made no difference on the vibrations it made no difference with the sound in fact that gear howling noise that i've been having problems with since forever i'd say it got louder and actually comes in sooner so the idea that thicker gear oil will reduce howling noises or gear wine or reduced vibrations not in my case so and from the video you can obviously see there's something bent in our axle i'm guessing it's the axle itself which would be the second time this axle has been bent and it just doesn't make sense i don't understand it um i'm i had a bit of a loss of words on why that could be but something is definitely messed up in here so before someone says that maybe i hit a pothole or a bump that bent the axle or caused damage to that left corner this is the front wheel as you can see there's no damage there even though it is a skinny wheel and this is the rear tire which has a lot of sidewall and there's no damage to the wheel as well so obviously i'm pretty f and pissed and quite devastated because i spent way too much money and time on this and i don't understand it the only thing i can think is maybe there's something wrong in the axle housing it's bent or some sort of irregularity in it that's causing it to screw it up especially on this side and it's been like that since day one because if you followed my channel i've documented it throughout the whole time that i have had problems since the day it went in the car in fact i've had problems since before it even went in the car and it's just getting too much so if anybody has any ideas or comments throw it in the comments i'd love to read it if moser somehow watches this video please do something help me out i mean we're talking like ten thousand dollars in three years now and i just want to enjoy my car and this isn't good enough it's just not good enough hit the like button subscribe thanks for watching

Channel: SS454LS6

Views: 22,236

Keywords: Chevelle, Wheel vibration, tire vibration, vibrations, driveline vibrations, tire runout, wheel runout, brake runout, axle runout, bent axle, Moser, Wilwood Brakes, 12 Bolt, 1971 Chevelle SS, pinion angle, driveline angles

Id: EKhmVWmqynk

Length: 11min 47sec (707 seconds)

Published: Sun Jun 05 2022