Can someone help link me to info RE 318is LSd upgrades

[vespam5]

I have not been able to figure out whether e30 325 and e30 318 rear ends are interchangable.

I'd like to get a 4.10 LSD into my 1991 318is (my diff is non lsd 4.10) and trying to figure out the right recipe, if anyone has done this or can help me find the right thread I'd really appreciate it.

Thanks

[87e30]

Your car should have come with a limited slip. Look for a tag on the back of your diff that says 4.10 and see if it says 4.10s. Or there is an S somewhere, that means it's an LSD.

I know the 4.10 came in the 318is and m3. Not sure where else you'll need to look to find one.

[xwill112x]

just get a auto 325is diff. medium cased diff, so you cant kill it with a 318 amd its a 4.10lsd. the 318is had the OPTION of a LSD, it wasnt standard btw.

[vespam5]

Thanks for the info guys. My diff is not an LSD since wheels spin opposite ways when off the ground and there is no "S" on the tag.

Are the 318 and 325 driveshafts/subframes/drive axles/etc the same? Diffs swap out between all e30s?

[vespam5]

Also I heard e28 diffs work if you swap out the back covers, will other diffs work too (e36 maybe)?

[BraveUlysses]

You can swap in any e30 medium case differential or a small case 4.10--no need to worry about driveshaft length.

[naplesE30]

You can swap in any e30 medium case differential or a small case 4.10--no need to worry about driveshaft length.

This is all you need to know.

and yes like somone already said 4.10 lsd was an option in the 318is, they all came with a 4.10

[vespam5]

Thanks guys.

[87e30]

My mistake, didn't realize same came without the LSD. What a shame.

[Emre]

Are the 318 and 325 driveshafts/subframes/drive axles/etc the same? Diffs swap out between all e30s?

Yes, it's a direct bolt-on swap. Good luck finding a decent medium-case 4.10:1 LSD, though. All the good ones are gone. And it's probably not a great idea to swap a diff with taller final-drive ratio into an M42B18-powered car.