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I bought a used Torsen from Hawk’s with 3.42 gears attached and installed it in my 88 305 Sport Coupe, I got the preload and backlash all good but try as I might I cannot get the thrust block into the diff.
My c-clips are fully seated. I read about people saying it can hit the ring gear but that’s not my problem, the “spider” gears are too close together. I can move the axles to move them a bit but nowhere near enough to get the block into the carrier.
This is my first time putting together a differential so I’m very new to all this.
Once the c-clips are on, make sure you pull the axles as far towards the ends of the tubes as they will go. I struggled for a bit getting my Torsen back together after I did my rear brake swap, but it turns out that the axles just need to be pulled ALL the way towards the ends of the tubes (as far as they'll go with the c-clips, anyways).
Probably a stupid question, but I see you have an '88... did you get new axles as well? And are they thirdgen length? Assuming you got a Torsen from a 4thgen, you'll need the 28 spline axles from a late thirdgen (90 or 91-92). If you're trying to get 4thgen axles installed in a thirdgen rear, they aren't going to fit properly.
Once the c-clips are on, make sure you pull the axles as far towards the ends of the tubes as they will go. I struggled for a bit getting my Torsen back together after I did my rear brake swap, but it turns out that the axles just need to be pulled ALL the way towards the ends of the tubes (as far as they'll go with the c-clips, anyways).
Probably a stupid question, but I see you have an '88... did you get new axles as well? And are they thirdgen length? Assuming you got a Torsen from a 4thgen, you'll need the 28 spline axles from a late thirdgen (90 or 91-92). If you're trying to get 4thgen axles installed in a thirdgen rear, they aren't going to fit properly.
Try as I might with multiple people, the gears don’t want to come out far enough to get the block into. The driver’s side gear moves about 1/8” but the passenger side gear doesn’t budge at all. I’m considering putting in on the bench to see if something is jammed up. I really don’t want to pull it apart again. I’ve tried pulling, turning same direction, different direction. No change.
As for the axle shafts, yes. I picked up a set of Ten Factory MG22103 shafts which seem right as all the way in they were just in far enough to get the c-clips in. Just like OEM.
Im assuming the diff is originally out of a 4th-gen based on the design. The listing just said 82-02. I trust Hawk’s to not sell me a dud diff but I’ve emailed them as well.
Right on, those should be the correct 28 spline shafts then. The diff is most likely from a 4thgen, don't think Torsens ever came in thirdgens, but could be wrong. My diff also came out of a 4thgen ('02 iirc), and bolted into my thirdgen rear using the factory 4thgen shims and all; also bolted my original ring gear to it so I didn't have to mess with the pinion. The 10 bolts in thirdgens/ 4thgens are basically identical as far as the center section is concerned,
When you say the gears won't come out far enough, what are you referring to? The only thing you should need to remove from the Torsen to install the axles would be the center plate, gears should just stay where they are... trying to picture what else could be hanging up. Are you putting the plate in the right way? The retainer bolt eyelet is offset, should only slide in one way; been a couple years since I last tore into mine, but I want to say the eyelet should be angled upwards when you go to install it. If that doesn't get it, and you're 100% sure the axles are both pulled as far out as possible, I'd try removing the C Clips, pulling the axles out a couple inches from the diff carrier, and see if you can get the center plate in without the axles. Should slide in no problem with no axles to get in the way
I’m not super sure on the terminology but the spider gear equivalents of the Torsen. Worm gears maybe? The gears the axle shafts mate to.
The diff came out of the box with the thrust block/plate removed and I never bench checked it but every picture I’ve seen shows it being the right on for that diff.
I am doing it with the notch upwards but the block won’t even go in past the front taper to get to that point. I’ll give it a shot again with the shafts full removed to see if that makes any difference.
I just ordered a crush sleeve eliminator so if I have to pull it apart multiple times I won’t need to mess around with that anymore.
Gotcha, yeah those are the worm/ helical gears. As far as I'm aware, they shouldn't move or pop out of place on their own, bit odd that it was shipped with the center plate not installed though... if you do have to pull the diff out again, you won't need to worry about the pinion, just make sure you keep the carrier shims organized so they can go back in the same spots. If you already made sure your pinion clearance/ backlash and all is good, then the pinion can stay right where it is. If the center plate still won't slide into place with the axles out of the way, then I suppose it's possible that one of the side gears could have shifted out of place slightly... you could try turning the diff with the car in neutral slowly while pushing each gear towards the side of the car (one at a time). Could also be possible that one of the axle c-clips shifted slightly when being pulled into place, which would mean that one (or both) axles were not fully seated. I usually hold the c-clip in place, then push the axle in place from inside the diff to make sure the clip doesn't fall or come out of it's slot at all.
I think I set the pinion preload a little tight so worth a double check. The pinion seal I got with my rebuild kit was wrong and wasn’t actually touching the yoke when I set it. So just to be sure I want to check again. I’m building the car for autocross so I’m expecting to have to pull things apart in the future anyways.
I think I’ll put the diff on the bench this weekend and give it a once over based on your information. The diff came with old bearings attached so my guess is that they literally just remove them, clean them, and ship them. Maybe the worm gear got a little cockeyed in transit.
I was hoping to have it together for my first event this weekend but I’m also not going to rush while I’m waiting for a proper pinion seal.
Preload should be set with no seal installed. The drag of the seal will alter the torque reading (make it read higher than it really is) and will lead to not having enough.
Incidentally LLCool, the RPO code for the 3.1 engine is LH0 (zero), not LHO (capital O).
If the center plate still won't slide into place with the axles out of the way, then I suppose it's possible that one of the side gears could have shifted out of place slightly... you could try turning the diff with the car in neutral slowly while pushing each gear towards the side of the car (one at a time). Could also be possible that one of the axle c-clips shifted slightly when being pulled into place, which would mean that one (or both) axles were not fully seated. I usually hold the c-clip in place, then push the axle in place from inside the diff to make sure the clip doesn't fall or come out of it's slot at all.
I followed your previous advice, removed the RH axle from the equation entirely, wiggled the driver's side axle shaft a bit and the gear popped into place. I got the plate installed over lunch. Thanks again!
Originally Posted by sofakingdom
Preload should be set with no seal installed. The drag of the seal will alter the torque reading (make it read higher than it really is) and will lead to not having enough.
Oh yeah I'm definitely over torqued then. Upon further investigation it looks like it should be 12-15 in-lbs and I had it at 20 in-lbs as that was what I had found for checking wit the seal in place. Which mine wasn't actually anyways. So hopefully the fixed spacer should be the ticket I need to have it be one and done. I got the backlash to .008" and the pattern seemed pretty close to what was on the gears originally so hopefully my first ever diff rebuild doesn't immediately explode once I fix the pinion situation.
20 is fine. I like to set mine up at 20 - 24. Of course with the solid spacer and shims you don't have infinitely fine adjustment anyway; the shims give you .002" or .003" increments or whatever they are, so they're like "steps" that you can get the preload to anyway, although I can't really say how many in-lb is gained by losing each .001" of shim. The high side of the "spec" is better than the low side. Same for backlash: remember, gears get HOT when running, and HOT metal GROWS, meaning, backlash GOES AWAY (becomes closer to zero); we all know what happens when 2 moving parts try to occupy the same volume, and we don't like it. For a street car with no power, the stock spec is fine. For heavy-duty use, open it up acoupla .001"s. Don't forget also, to get as much preload on the carrier bearings as you can. I like to get at least .005" more shim on each side in there than "zero lash", preferably .010".
