Like I've said previously, I had new seals put in my diff. The driveshaft seal, halfshaft seals and rear cover seals have been replaced. I took it back to the shop to trace a small leak two weeks ago. He replaced an o-ring that goes around the speed sensor, and thought he fixed it. It's still leaking, so I went back, and now he says the speed sensor is where the leak is coming from.
Not a big deal, I can replace that easily.
The questions is, can the speed sensor really be where the leak is, or is the o-ring still the issue? Second, should I buy the speed sensor made for the 3.46 LSD, or buy a new one that fit my stock diff?
The part #'s are different, and from the picture, something else is different on the socket where the wires come in.
Here are the links.
http://www.realoem.com/bmw/showparts...09&hg=33&fg=10 http://www.realoem.com/bmw/showparts...31&hg=33&fg=10 In the first link, part #11 is not familiar, doesn't show in the stock TI part list.
I am currently using my stock TI speed sensor in the E28 diff, and it works fine. So which speed sensor should I replace it with, or should I just try something else to fix the small leak?
Speed Sensor 
Threaded Mode