Differentials

[e30serg]

OK. So I know I need to use an e28 (528, 533i, 535i) diff or z3 diff since they have the medium case.

What about the e36 m3 3.23 LSD?

My question is: Can you just swap the internals from the e36 M3 into an e30 case?

I have both an e28 533i diff (assuming 3.25 LSD) and an e36 M3 3.23 LSD diff.

The thing is, the e28 diff is still on the car sitting in front of my house, and the e36 diff is on my garage floor, ready to be taken apart.

[PiercedE30]

You can swap the internals, but it is tricky. You have to set up the back lash and the preload on the pinion and check for proper gear mesh and go back and adjust the pinion. But other than that, it's easy as pie.

[windsor318is]

You can swap the internals, but it is tricky. You have to set up the back lash and the preload on the pinion and check for proper gear mesh and go back and adjust the pinion. But other than that, it's easy as pie.

please tell me that you documented that...or no a good read!

[PiercedE30]

HAHAHAHA...hahahaha.....ha
No, I have VERY limited knowledge about the rear ends. I would love to be able to do that, but I don't. The most I have done is torn down and documented and rebuilt/reassembled a limited slip unit. I have LONG post in the transmission and driveline subforum (same one is stickied over on E30Tech), just search for "See what the inside of an LSD looks like."

[Mr.SWISS]

I used the std E36 325I trans on my swap and went with te 87 535is diff. 3.25 LSD ratio for $100 bones was hard to beat. I found it to be a very good balance between daily/ highway drivable and sporty.

[318isbmw]

Its not too bad setting backlash and such on a diff. Take a lil time and get lots of the paint on stuff for knowing what a good mesh looks like if you go that route. Doubt your gonna find much bmw stuff on doing it, but check out some hotrod sites and search around a bit, we do it tons haha.

[PiercedE30]

Yea, I think you can get a pack of pinion shims from the dealer or something for like 70 bucks. You can probably get it cheaper elsewhere though.

[euro3]

Before you worry about backlash setting (something I would pay to have done) you need to know what size your ring gear is.

The larger (E30) ring gear is 188mm.

The E36M3 3.0 ring gear is 188mm.

The E36M3 3.2 ring gear is 210mm.

Some E28 diffs are also 210mm.

You can get this info from the parts manual (ETK, Real OEM).


G/L

[PiercedE30]

What E28's came with 210's?

[gobuffs]

The E36M3 3.2 ring gear is 210mm.

Only on the Euro, the US M3 3.2 is a 188.

[e30polak]

If your going with the e36 tranny just use the 3.25, the gearing is pretty nice. Even though I want something in the 3.4Xs or 3.5Xs, I don't have the money to pay someone to install new gears :(

[z31maniac]

What E28's came with 210's?

M5?

[PiercedE30]

Yea, but other than that.

[m3_eater]

If your going with the e36 tranny just use the 3.25, the gearing is pretty nice. Even though I want something in the 3.4Xs or 3.5Xs, I don't have the money to pay someone to install new gears :(

+1. I have a 3.46, and it was too short with the ZF 5-speed for DD duty. It's perfect with the E46 6-speed, though.

[tjts1]

You can ge a 3.23 or 3.46 from an E34 as well. No need to swap the internals. Just the rear cover and axle flanges.

http://www.e30tech.com/forum/showthread.php?t=57743