The E36 Diff Thread

[kevinwilly]

So more nooby questions incoming but how do I measure carrier preload? And the only way to adjust pinion depth (and backlash) is with the shim and crush sleeve correct? I didn't measure my backlash before disassembly partially because I knew I wanted it tighter. I've got thicker shims, but will likely require more adjustment than just the shim. That adjustment is taken up in the crush sleeve right?

Thanks for the help guys, much appreciated.

You measure carrier preload by measuring the rolling resistance. If you are not replacing bearings then DO NOT adjust your preload. It will go down once the bearings break in a bit.

You adjust this resistance by increasing the TOTAL shim thickness on the carrier (the sum of the left and right shims). Thicker shims=less preload. Thinner=more preload. Once you get that number save it. You will need to adjust how much of that total is on each side to get your backlash and/or wear pattern set correctly. Mostly the carrier shims change the backlash.

So you need a torque wrench that is a beam-style or dial-style that reads inch pounds. A clicky-style one won't work.

The PINION depth is adjusted by the pinion shim. That mostly changes the wear pattern. And to a lesser extent the backlash, but really mostly wear pattern. The crush sleeve sets preload ONLY. So you get everything adjusted and the VERY last thing you do is set the pinion preload before doing a final assembly of the carrier and closing it all up. because that crush sleeve can't be reused. For mocking up the wear pattern and the backlash and whatnot you just need it snugged down so it doesn't have any play. It doesn't need to be preloaded. Again- if you are NOT replacing your pinion bearings, then measure the preload before you remove the pinion and then reinstall it with THAT amount of preload. Otherwise you will overload bearings that are broken in. That's bad.

So yeah- if you are ONLY changing the backlash and not swapping out the bearings, just measure the shims on your carrier now. If you have a 1.3 on the left and a 1.45 on the right, then you need 2.75 worth of shims. To get rid of backlash you need to move the carrier to the left. There's a thing I read somewhere for how much shim eliminates how much backlash. Maybe it was in this thread. THAT can help you save some time (so if you want to get rid of .007" of backlash you know you need to shift X amount of shim from left to right. I forget the number off the top of my head)

Hopefully that makes sense?

[lbennyboobool]

Hopefully that makes sense?

sounds like you've done this a few times

[kevinwilly]

sounds like you've done this a few times

Only once, actually. At least on a BMW. But differentials are all basically the same and I've been playing with them on and off for the better part of 20 years.

[Foda420]

Only once, actually. At least on a BMW. But differentials are all basically the same and I've been playing with them on and off for the better part of 20 years.

I've read your post a few times and it definitely clears up a lot of the questions I had. Hopefully I can use that well and actually get it setup right! I'll be working on it this week in my free time at work, hope to install this weekend. I'll update with progress and maybe PM you with problems LOL

[Foda420]

Finally finished! Here's my "homebuilt" 3 clutch 3.46 differential. It's sitting at work with the gasket curing, will install Monday night. Big thanks to @kevinwilly for the help!



Sent from my SM-N920P using Tapatalk

[aeronaut]

Nicely done! I keep putting off buying some 3.46 gears and doing this. But a seepy input shaft seal may push me along.

[PMed]

Hi guys,

I'm planning on dropping in an e36 M3 evo LSD into my e46 M3 casing, and have question regarding replacing/upgrading the clutch discs.

I've found a company that manufactures clutch plates for the e36 210mm LSD. One option they have is an 8-plate kit. The space for the 4 extra discs comes from removing the two concave belleville discs. However, I thought these were intended to provide preload to the LSD assembly. What's going to happen when they're taken out?

Thanks

[3literheater]

I am rebuilding my 210mm unit for my transmission conversion. I replaced all of the bearings and have a new set of 3.64 gears rather than the 3.15 gears that were in there.

Being that this is my first time building a diff I wouldn't mind a little input.

I assembled it with all of the stock shims from the 3.15 gears and I got .003" of backlash and the pattern looks like this:






To me it looks like the pinion should move a little towards the carrier? What do you guys think? I added a .0075" shim to the stock pinion shim and it really messed up the pattern. So I know now .0075" is too much to maybe make the pattern more ideal.

Also when I took this diff apart the backlash on the 3.15 gear set was .005" and now with this 3.64 gearset I am at .003". Is that too tight? I don't want to burn this thing up.

I know the 210mm unit is sligthly different than the 188mm unit, but any help/advice would be appreciated.


Thank you!

[RRSperry]

I'd contact Jon Theyer, or Dan at Diffsonline... Maybe they could be more help.

[f0xy]

Has anyone had an issue of not being able to get thin enough carrier shims? I've got the thinnest shim on the passenger side and the third thinnest shim(used the 2nd thinnest shim on another diff) on the driver side. Preload is still on the low side, but getting close, 1 or 2 sizes smaller should get the preload in spec. However, there's zero(negative actually) backlash, I played around with pinion spacers to see how much effect that would have on backlash but it didn't change backlash much. I think I narrowed it down to the new TIMKEN carrier bearings being ~.005' thinner than the original FAG bearings. Apparently the original FAG bearings are no longer available, at least through BMW. Has anyone else had an issue like this? I think I'm going to try SKF and see if that helps.

Long time since your post, but maybe someone else can help either way. I'm having the same issue at present.

Built a couple of these diffs before, using the 'standard' LSD unit, all went together and shimmed fine with new Timken bearings in the past.

I'm currently in the middle of building a new unit with a 188mm Kaaz LSD, using 3.64 ring gear and pinion. The carrier preload is set (3.02mm total shim size), which is fine. The issue is I'm getting zero backlash. I have 1.57mm on the crownwheel end, and 1.45mm (the SMALLEST shim) on the other. Because of this I can't physically shim the crownwheel any further away from the pinion to get any backlash.

I have a handful of pinion shims, but what is the general resolution for this? Surface grind the shims? Try different bearings? Reduce the pinion depth?

[wanganstyle]

Long time since your post, but maybe someone else can help either way. I'm having the same issue at present.

Built a couple of these diffs before, using the 'standard' LSD unit, all went together and shimmed fine with new Timken bearings in the past.

I'm currently in the middle of building a new unit with a 188mm Kaaz LSD, using 3.64 ring gear and pinion. The carrier preload is set (3.02mm total shim size), which is fine. The issue is I'm getting zero backlash. I have 1.57mm on the crownwheel end, and 1.45mm (the SMALLEST shim) on the other. Because of this I can't physically shim the crownwheel any further away from the pinion to get any backlash.

I have a handful of pinion shims, but what is the general resolution for this? Surface grind the shims? Try different bearings? Reduce the pinion depth?

Do you have the bmw tis document regarding differential service and setup ?

I would suggest starting from there.

Kaaz units in my own hands have fit happily in place of Oem bmw when setup properly.

If there is 0 clearance between ring and pinion the fundamental case setup is incorrect; the bmw factory document has good data on setup

[f0xy]

Do you have the bmw tis document regarding differential service and setup ?

I would suggest starting from there.

Kaaz units in my own hands have fit happily in place of Oem bmw when setup properly.

If there is 0 clearance between ring and pinion the fundamental case setup is incorrect; the bmw factory document has good data on setup

I do, and I ended up using a different casing.

It then shimmed fine - pattern and backlash all good. Its been in use for 4 months now!

Cheers.

[tjm3]

How did you arrive at the shim pack thickness for the pinion depth?

Long time since your post, but maybe someone else can help either way. I'm having the same issue at present.

Built a couple of these diffs before, using the 'standard' LSD unit, all went together and shimmed fine with new Timken bearings in the past.

I'm currently in the middle of building a new unit with a 188mm Kaaz LSD, using 3.64 ring gear and pinion. The carrier preload is set (3.02mm total shim size), which is fine. The issue is I'm getting zero backlash. I have 1.57mm on the crownwheel end, and 1.45mm (the SMALLEST shim) on the other. Because of this I can't physically shim the crownwheel any further away from the pinion to get any backlash.

I have a handful of pinion shims, but what is the general resolution for this? Surface grind the shims? Try different bearings? Reduce the pinion depth?

[wanganstyle]

How did you arrive at the shim pack thickness for the pinion depth?

The bmw technical document details this.

It is much suggested to read and try to comprehend the factory instructions

[tjm3]

Yes, bmwtechinfo (.com) has ALL of the factory instructions. Goes without saying. I might be willing to bet that not many have the required tools (BMW factory/dealer tools) to measure and set pinion depth, and I still don't have the answer to the original question to the poster with the original problem.

How did you arrive at the shim thickness for the pinion depth?

[BoostedBimmer]

All of the pictures on the OP are down. Can we fix this?


Sent from my iPhone using Tapatalk

[Cesconeto]

Hello smart ppl from the interwebs, Im doing the following operation:

IMG_20171127_152817443.jpg

And would like to know what would be the simplest way to accomplish it. What parts from what diff to use in order to achieve the result with the least chance of reshimming? I will not be replacing the bearings nor seals.

Thx in advance

[TehE39]

I just recently replaced the gears and all the bearings in my 188mm e36 lsd and I am experiencing intermittent groaning noise only under tight turns and parking lot speeds. I took the rear end to a reputable shop in my area that only builds rear ends and I replaced all the bearings with units from Thayer but I didn't pop open the carrier since the diff's breakaway torque is right at 53 ft lbs. What's odd is sometimes it makes no noise at all when its cold so I am beginning to think the dog ear plates are worn out or maybe something is up with one of the clutches?

[tjm3]

You don't have enough friction modifier in the diff fluid. It's NOT all the same. If you used anything but the BMW fluid then is gonna be hit or miss on whether you have enough friction modifier in the fluid to prevent that noise. I know, I know, that a lot of different fluids are in use and everybody swears by the stuff they use, BUT, the only way to go noise and problem free is to use the BMW original SAF-XJ . You can always squirt in some redline friction modifier in small amounts until the noise goes away, or just use the BMW stuff. That noise at slow speeds and tight turns is a dead giveaway of LS clutch noise. I've always been able to get the bulk stuff from the local dealer with a couple empty quart bottles for about $15-20.

All this assuming the rest of the diff and associated parts are assembled properly.

[pbonsalb]

I have used various different fluids and never had an issue. Later cars like the E90M3 are more sensitive. Just don’t use 75W90NS since it has no friction modifiers. The package in most fluids that are for LSDs work fine in my experience.

[TehE39]

I just recently replaced the gears and all the bearings in my 188mm e36 lsd and I am experiencing intermittent groaning noise only under tight turns and parking lot speeds. I took the rear end to a reputable shop in my area that only builds rear ends and I replaced all the bearings with units from Thayer but I didn't pop open the carrier since the diff's breakaway torque is right at 53 ft lbs. What's odd is sometimes it makes no noise at all when its cold so I am beginning to think the dog ear plates are worn out or maybe something is up with one of the clutches?

Update: I added around 80% of the 4 oz Redline Friction modifier bottle and the noise is completely gone. It seems the 75w90 Royal Purple MAX GEAR oil didn't have enough LSD additive in my case.

[zzvvmm]

Hello, does somebody know how mm should the top cover of typ 188 lsd opens up when all 8 bolts are removed ? I have noticed on some it is 2mm and on other is 4mm..

[TH3 Shifty]

anyone know what i need to upgrade my diff from the 3.23 to the 3.38? what parts are required...

[RRSperry]

Two things.

IF you have a later 4 bolt driveshaft. (just look at the front of the diff. are there 4 bolts or 6) you just install the diff. If you have a 6 bolt driveshaft, you will have to swap the input yoke on the diff. The problem with that is you also have to replace the crush sleeve and set the preload. The nut is also torqued to something like 129 lb-ft and you have to lock the output flanges.

And yes, people do just say Fk it and swap the yoke, but if you screw it up, you can burn up the diff.

[TH3 Shifty]

i have a 4bolt... but what i should have said was, i want to CONVERT my 3:23 to a 3:38... what parts do i need? just the new gears?