Oliver and White's Over Under Transmission - What is it?

oliver's over and under drive what is it had a few requests and uh kind of the basic operation of it it is a three-speed auxiliary transmission that mounts down there between the engine and the main transmission it's a shift on the go unit uh levers over here on the side on pretty much all the olivers if you have over and under if you have hydropower it's down here but uh you pick your gear and oliver's barely had six forward speeds and two reverses and basically it's just a three-speed forward one reverse with a range shift that used with the same led lever instead of having to have two separate levers to shift so you pick uh say you want to work in third gear that will get you up around uh around five mile an hour i think in overdrive so you pick third gear and then once you're in it under is the slowest and that is a mechanical gear it's a works with the sprag clutch which is a one-way clutch so the tractor can roll downhill faster than the engine's going so it's one you want to be careful with um because it can speed up on you direct drive is a clutch pack it's a power shift clutch pack that it's the strongest of the three ranges so if you're really pulling something hard and worried about uh maybe breaking it or working it too hard directs your one to be into and then overdrive uses a planetary gear set to speed the output up so under drives about 20 percent slower it depends on the over and under unit they change the gearing in them a little bit but about 20 17 20 slower than if you're in third gear and third gear is normally four mile an hour you'll slow down 20 percent compared to direct which would be the same as if there was just a straight shaft in there all that does is direct drive is connect to shaft then on the clutch to the transmission end no gear reduction or speed up so under drive will give you about 17 slower speed more pull go up to direct uh speed you back up to the uh engine speed of the shaft and overdrive speeds you up about 20 percent faster than what the engines turn in so it gets you another range on in a field uh generally these three speeds on most conditions will get you what you need you can um uh shift up and down uh i use them when i'm on the field i don't matter what rpm horse there you know i use them shift them when i want to you don't have to clutch or anything just move the lever and uh the only time i do get take it easy on them is going down the road uh you got a lot less gear reduction so and there's a bigger jump in speed you know from under drive wide open i think is around like 13 mile an hour on this tractor um i think you jump up to around uh 16 or 17 in direct drive and then up around 20 in overdrive so you're talking a big jump in speed you don't have as much gear reduction and and so it's just it's a lot harder on the main clutch it's a lot harder on the over and under so what i do is i get about half throttle and then shift up shift up and then uh throttle up the rest of the way and that way i'm not putting full horsepower through it or the main clutch it just uh seems work good on them and then when i'm slowing down they say don't skip gears but it's like if i'm coming down the road and i'm in overdrive i'll throttle back some but i you don't want to like be wide open and just dropped it direct especially if you got a big load behind you that puts a lot of backlash on the gears and i've seen a couple of plates hold the input shaft kind of bent out from that because of the shock load or whatever you want to call it from the sudden slow down so i just leave it over and use the engine to throttle back and then when i'm getting slowed down then i just jump all the way to under drive and let it coast until the engine or the slip tractor slows down to engine speed then uh throttle down some more and just depends on you know if i'm just going uh pulling in a driveway and i can slide it into the next gear but that works good for me other than that if i'm in the field and if it's wide open if it's half throttle up i'll shift it whenever no need to use the clutch or anything they're heavy enough for that as far as checking them out check the oil usually oliver used automatic transmission fluid dexron 3 is a good replacement for that so if it's red in color that's what's in there if it's the clearish to light brown then it's it's a universal most likely that's a good substitute if you're gonna clean it or change it all at once but a good test for these is to drive up a hill because the way they're designed and direct and over they cannot turn backwards and so that's what makes them shift hard the main transmission if you want to make your shifting easy always shift to under drive before you shift gears because a good over and under will hold pressure and can't turn backwards and and so that puts a bind against the gear just really makes it hard to shift this and just always shift down to under drive that and it's easier taking off with your clutch uh if you're on under drive the lowest speed but one thing i found is if you drive up a hit a somewhat steep hill and uh and then hit the clutch but leave it in overdrive it might it should take it a few seconds before it rolls backwards because the pressure has to bleed off from the overdrive clutch pack let's try it oh i'm in gear and my say neutral safety such works neutral safety switch oh push the button i think this should be enough of a hill right here i'll do it in under drive first should start rolling backwards yep okay now i'm gonna go up to direct and with it and direct see how it won't roll backwards now it will that means it's pretty good uh direct drive has uh ceiling rings that can bleed off quicker than overdrive so if it holds for a second or so it's doing pretty good it doesn't take long for the pressure to breed off from over or under or direct now see over yep the pressure bled off then it can roll backwards but it took it a second or so so this one's holding good that doesn't guarantee there isn't a guarantee that everything's not worn out inside but it's at least good enough to where it won't leak off as quick i've seen him hold a lot longer than that i haven't been through the over and under in this unit so but i haven't had any problems with it slipping either and there it goes let's try drag yeah direct didn't last very long they say the nature of the ceiling rings on the shaft make direct uh leak down a little faster here we go don't have to use clutch shift down [Music] one of these days i'll make a repair video video for these i just got to get one to work on but i hope everybody found this informative useful here's another hell and i appreciate everybody watching this one ain't as steep of a hill it's not gonna let it roll as fast or at all hey everybody once again thanks for watching and we'll see you in the next one

Channel: That Oliver Guy - Chris Losey

Views: 13,058

Rating: 4.9590268 out of 5

Keywords: oliver, tractor, farm, white, equipment, over under, 3 speed, transmission, powershift

Id: -ajlOhilj4M

Length: 9min 51sec (591 seconds)

Published: Sun Oct 11 2020