I just got my E92 a few weeks ago with 18,500km on it. It's now at 18,800 and I'm noticing the "clunking" mentioned earlier while shifting and letting off of the clutch. I am also hearing the grinding noise but thought it could be related to the clunking.
My question to those that had their diff fluid replaced with the updated fluid and friction modifier is, does BMW do this free of charge? It seems, since they issued a service bulletin that they have identified a problem and have a solution. As opposed to the post about the "clunking" being part of normal operation. It stands to reason that if the grinding noise in the diff were normal, they would just tell us to deal with it.
Since it is a documented problem, will they just fix it under warranty, no questions asked?
Thanks in advance.