LSD retrofit

#1

I’m looking at some E30 models for sale and was wondering if it’s possible to retro-fit a non-LSD with a factory LSD? If so, is possible how tough a job is it? Thanks!

#2

You have to swap the diff. You can’t swap the guts of the diff. Swapping out the diffs isn’t rocket science but there’s a helova lot of bolts involved.

You can get a used LSD diff for not too much. Be sure to test any diff you recieve tho. If I recall correctly, BMW’s spec for LSD slippage is 35ftlbs, but most of us consider that to be pretty weak. A good strong diff will slip around 55ftlbs.

There’s some other posts worth checking here, do some searching. That will give you the test procedure and my usual hundreds of posts about not much.

Think of this as an opportunity to install a diff vent tube.

#3

Man! I thought this was about a “LSD retardo fit”. I was like, man!!! I know about those. But I was think of somethan else.

carry on

#4

Thanks for the info Ranger. I’ll poke around for a write-up about it. I’m Bentley manual covers it pretty well also.

#5

actually ranger is wrong. You can swap out the guts, its just not worth the effort,because there are still a lot of 3.73s out there cheep.
I’ve rebuilt several diff’s for srec 30 guys,I charge $400.00 plus a usible core.
BD

#6

bdigel wrote:

[quote]actually ranger is wrong. You can swap out the guts, its just not worth the effort,because there are still a lot of 3.73s out there cheep.
I’ve rebuilt several diff’s for srec 30 guys,I charge $400.00 plus a usible core.
BD[/quote]
Oops. Brendan has forced me to put more braincells on line and better recall the saga of the stolen diff. He’s right, I’m wrong.

#7

The bolts holding the axles to the diff: are these single-use type or can i just re-use them? Should i use threadlocker? Also i assume this is a good time to replace torn CV boots - yes?

#8

Those bolts can be reused. I’ve never put thread locker on them and never have had them loosen, but Locktite Blue wouldn’t be a bad idea.

If the CV boots are torn, replace them and re-pack the CV joints with grease. That may postpone having to replace the CV shafts for a long time if caugth early enough.