What diff do you think this is?

[david220]

Ran across this, supposed to be out of a late '80s e30; has an 'S' stamped in white on the top along with a '54' ; looks like two serial numbers which could be just case part #'s one is 66640 and the other looks to be 1210311 which could be the case BMW part #. The fellow said it was a 4:10 LSD. I am thinking about putting it in my '91 318is; the lower front mounting needs rethreading but other than that seems fine. Thoughts? Looks a bit larger in the rear than the one I took out, so I do not know if it will clear the sway bar. David

[jpod999]

There should be a little metal plate on the back of it with a number stamped into it. If it is a 4.10 LSD then it would say S4.10. If it is open then it would just say 4.10. That goes for all the other gearing ratios too.

[david220]

It is a 4.10, rethreaded and bolted up; I am going to clean up and go through the old one, shouldn't hurt to have an extra.

[david220]

Finished installing the LSD and got the rear springs and shocks done, took it out for a short run to settle things in and there is a noticeable difference with the 4.10. I need to do the front springs and shocks before getting over 3rd so I do not know what happens on the highway. It is a good swap to do for sure. David

[nickmpower]

stock is 4.1

[jpod999]

What ^^ said. If you didn't have a 4.10 LSD before, then you probably had a 4.10 Open.

[david220]

Yes, I did not have LSD before.

[Donkeyshins]

Yes, I did not have LSD before.

Dude, you are so missing out...trails, beautiful trails...:D