E30 318is Differential Z3 LSD swap

[Fergi]

Hey folks, I have a 91 318is (M42) with a crapped out open 4.10 dif, and am looking to get an lsd since it needs replacement anyway. The current dif has a deafening whine that I cant live with anymore lol. Ive done a bit of research and think i would like a torsen lsd from a z3 cause they have good longevity. Does anyone have experience with putting a z3 dif into a 30? From what ive read its simple as swapping the flanges and popping it in. I've also heard people say it's not, the speed sensor wont work, and that you will have to adjust preload and other settings. Does anyone know for certain if this will work?

I was looking at picking up something like this ebay listing https://www.ebay.com/itm/166527010421?mkcid=16&mkevt=1&mkrid=711-127632-2357-0&ssspo=zfohmoexq4c&sssrc=4429486&ssuid=eYNrzbGn RD S&var=&widget_ver=artemis&media=COPY

I dont mind the 4.27 ratio, i never drive on the highway (i have a vw gti i take long distances) so i would love a bit more acceleration.

Anyone bought a dif from ebay? lol. any info would be appreciated before i send it, thanks!!

Heres a pic of my 30 for fun as well

[sna77]

You can also order one for your car with everything you need... I just bought one for my '92 318 convertible from diffsonline.com

[Vincenze]

The speed sensor that comes with a Z3 differential should work. You just can't put the one from a E30 differential.

You can also check Z3 for sale groups on Facebook and https://www.car-part.com/
Shipping will be expensive.

You should do research. Only 6-cylinder Z3s had Torsens.

[packratbimmer]

188 is easy, but the 168 requires special seals since the output flanges are a different diameter where is meets the seal.

[AceAndrew777]

After taxes and shipping your looking at north of $700 for a used LSD core. That's nuts, someone's wishing upon a star for a sucker to come along (but it's eBay parts pickers, so what else is new). Total value should be around $400-$450.

I'm used to doing 168mm LSD's for 2002's, so my experience here isn't much. However, if you're swapping the pumpkin into your existing E30 diff case then you will need to re-shim the side covers for the correct lash. As long as you're swapping the ring gear over then there's a decent CHANCE that it'll still be at a usable spec (pinion depth), but you WILL need to check and be prepared to change it if needed. Side cover shims can be frustrating to source (at least they are for the 2002 and E21).

Output flange and seal compatibility is outside my area of experience.

[82eye]

there's a good chance you can rebuild the original as well if it was a limited slip. i've rebuilt and ls unit swapped a few different diffs including a couple bmw.