New info on diff fluid
OK, I had the diff fluid changed today. Here is the scoop.
There is a TSB out #31-01-02 on Differential Noise. According to it cars made 09/02 and later have a changed diff, but for the earlier ones, if the customer complains about grinding noise in low speed turns (hint), the fix is to replace the diff fluid with the new stuff, 83-22-2-282-583.
At first they weren't going to do the change under warranty until we looked up the bulletin and I told him the diff was noisier than our M Roadster.
I don't know if this fluid will help preclude problems with the "old" diff, but I figured it can't hurt.
BTW going through the fluid/additive/fluid thing was all the same dealer and same parts people. Can't BMW get some people who know something?