Need help asap BMW diff. related
 

Long story short,

I sold my BMW to a guy in L.A. and the input shaft bearing on my diff went out on the drive down here. It's a 85 635csi with a 3.46 LSD

Went to the wreckers and got a open 3.45 off what he said was a 325 (a LSD 3.73 was $100 more), although when I got home, I see the diff cover has a completely different rear cover and housing. The old diff cover will not line up, although the output shafts do.

I'm suspecting it's out of a E36 based on some basic research of part numbers on Pelican. Anyone know what this is off of? Diff tag reads 345 N5701. The cover reads 1214110

I've included a pic of the diff along with my original cover

I got to have this thing changed out by Monday

Guess I'm back there tommorow with more money, grrrr.....

http://forums.pelicanparts.com/uploa...1150513020.jpg http://forums.pelicanparts.com/uploa...1150513053.jpg

The E30 and E24/E28 differentials are interchangeable. You just have to exchange the stub axles and cover. Looks like you got the wrong differential.

Too bad you aren't closer. I've got a standard 3.46 open differential in my garage thats just taking up space. It came off my 635 when I swapped in a 3.73LSD.

It looks like you have a diff out of an E30 4 cylinder car, they're a small diff. In order to get a diff that will fit your E21 6-series, you need one from an E30 6-cylinder car, an E23 7-series, an E28 5-series, or another E21.

Then it's a simple matter of swaping the diff covers, swapping the stub axles (and maybe renewing the side seals, cheap), bolting it in (use a tranny jack), and hooking up the speedometer sensor.

Pulling the broken diff apart to replace the bad part requires a rebuild, at around $800.00. Not the thing to do.