Small case diff

[Turb02]

Will the internals (or entire diff) of a 318ti work in the 02?

I know, search! I'm at work and this site is proxied so I'm posting from my iPhone, which it tedious and time consuming to say the least.

Thanks in advance

edit: I sent an email to metric mechanic and the person that received the email showed it to their diff builder, Courtney, and he said yes. The internals will fit. Now I just gotta find out if anything else is needed other than swapping parts around...

[Guest Anonymous]

well since no one else is answering, it is my understanding that e30 (excluding m3), e21, and 2002 short diff ring and pinions set can interchange. Beyond that I don't think you can take the internals and directly swap, but the gears can be.

[Turb02]

What about the LSD unit? Ring and pinion AND LSD?

I'm looking at getting a gear ratio that's closer to 3.45 without the ginormous price tag of the 320/6 LSD

[TobyB]

Ok, here's what I've done. That's not to say it's ALL that can be done...

the 318 small case diffs well into the '90's can donate their gears to an E21

housing. If you keep the same gear carrier, I've never had to re- shim

anything to get a good tooth contact pattern.

I haven't tried the 2002 case, but I vaguely remember that there's a clearance

issue with something, and it may be minor.

I use 320 rear parts anyway, so I never pursued this.

If you try to change the carrier (LSD spool) from one case to another,

you probably will have to re- shim the bearings to get a good contact pattern.

I HAVE found that the later 320 units are a lot more uniform than the 2002 stuff

(as in, almost all 320 diffs are very close to each other, while the 2002 diffs

have lots of different shimming)

The total stinker about re- shimming a 320 case is that the clever Germans

figured out that different thickness shims were easier to deal with than

lots of thin shims, so it's a real pain to change a 320 case by a few thou,

whereas with a 2002 diff you can just shift the thin shims around.

And the pinion's the same way.

fwiw,

t