E30 Zone

Hello

I compete in the BDC in my e30 M30 Turbo but currently running small case diff 4.1 and shafts.

I want to upgrade to medium case for strength but not sure if they fit my shafts aswell so is there an upgrade I can do without changing hubs. I know the compact rear end goes in so can I just change the shafts and diff from a compact E36 and still retain my prop?

any help much appreciated

A large case diff bolts straight on. Just need to shorten the prop a little.

What about medium case? I need a quick fix as I am out next weekend.

I mean medium case, just large case in E30 terms.

Maxfield means a medium case. Large case diff. won't fit at all, whereas medium and small are interchangeable with no problems.

sorry thought you meant large as in e34 large. will my shafts fit? as in are their larger shafts available or are all e30 shafts the same?

Small case is 168 (316 to 320i), medium case is 188 (325i and M3) and big case is 210, M535i etc - but no E30 used this and it's just too big. A 188 medium case will bolt straight in. The prop is shortened by undoing the collar nut behind the centre bearing and giving the end of the prop an smack with a hide mallet to push it in about half an inch unti it's just right. Bolt the diff in, bolt up the prop and then retighten that collar nut. Easy as.

Other cars use the E30's 188 diff - E28's apart from the 535is and many E34's such as the 518i, 520i.

Thanks Andy appreciate that clarification.