LSD Clutch Replacement FAQ

[athayer187]

After much research, I replaced the clutches in my differential. If you have the ability to remove and replace the differential, you should have no problem replacing the clutches (you just need to make sure you have a very clean workspace and keep everything in order). I rebuilt my differential 3 times messing with 3 clutch setup, Porsche clutch setup, etc. Lesson learned is stick with two stock BMW clutches unless you want a lot of preload on the LSD guts (lots of lockup = LOTS if chatter).

Parts to buy
2 x 33141210626 - LSD clutches (~$48)
2 x Porsche P/N 91733255212 - LSD dog ear plates (optional, ~$40)
8 x M8x1.00 x 20 hex head bolts - to replace the allen heads that hold the LSD guts together as they may strip (~$5)
1 x 33111210405 - differential gasket (~$5) (or just use RTV)
2 x 33111214144 - Outer race o-rings (~$2)
2 x 33107505602 - Output shaft oil seals (~$9)
Brake cleaner to clean the internals
Blue loctite

Rebuild
1. Remove differential
2. Clean outside of diff (pressure washer, simple green and brush, etc.). You don't want any of that junk getting inside.
3.LSDReplacement.pdf
4. Reinstall differential

How's that for a 4 step DIY?

Notes
- Limited slip internal parts are not listed in ETK under any E28, look up an 86 E24 instead
- Check backlash once everything is reinstalled. When you have the differential back together (just before you put the rear cover back on), try to wiggle the ring gear. You should get a few thousandths of an inch movement at most. Additionally, there should be little resistance when rotating the output shafts. Too much means something is wrong.
- Bimmerworld clutches seem to be the same as the BMW P/N, just more expensive
- You can test it like the spec E30 guys do. Jack up one side of the car, put a torque wrench on one of the lugs. You should be able to spin the wheel at somewhere between 40-60 ft/lbs for a fairly healthy stock diff (you're measuring static breakaway torque). Much lower than that, and I'd rebuild sooner rather than later for the best performance.
http://spece30.com/forum/48-drivetrain/ ... lutch-test
- Diff internal P/N's can all be found in realoem under a euro E23 or E24
http://www.penskeparts.com/DiagramsMain ... 3141206923