E30 Diff identification info

[bwh13]

I have been looking at the 4 diffs I have (including the one in my 88 325i)and they all have the same case number even though they came out of different series.

All are LSD, all have 1210411 cast into the case on the passenger side near the top. You can see it with the diff still in the car.

733i 5 speed
E30 325i
5 series (not sure which models)

I'll go back to the salvage yard where I found one of them and see if the non LSD cars also use the same case #.

This seems to be the easiest way to ID the case needed for the E30...

[AdamF 88iS]

There should be a metal tag attached to one of the rear cover bolts.

[92 mtechnic cabrio]

The tag is usually covered in grime. Won't take much to uncover the grime.

[bwh13]

I wasn't referring to the gear ratio, which as you noted, is on the tags, but rather to the case size question that keeps coming up.

Since the 'medium' case diff like in the E30 obviously can be used in other series, it seems like there has to be a common case casting to fit them all. That's where the number comes into play. Since it is the same for the three different chassis codes, it more than likely a good way to ID a case for the E30 applications.

There may be other casting numbers that also fit the E30 chassis, I just happened to note this one.