Originally Posted by mbdoc

In 1995, I was auto crossing a 1981 euro 280E & decided to make my differential a LSD!
I found out that no one ever offered that for the W123.

So I started measuring MB differentials & found that MANY MB's used a 185MM ring & pinion.

I bought a 16V differential from a junk yard & removed the carrier.
To mount the ring gear you need flywheel bolts & a 5MM spacer & bingo I had a W123 with limited slip.

About 3 years ago Tom W. contacted me & I explained just how to do that job.

So if you can find a used 16V differential, you are 1/2 way there.