Rear Differential Issues
My 2008 E90 M3 had it's 1200 mile service done and is now at 2,000 miles. In the last 250 miles it has developed what best can be called a groaning shudder in right turns that is slowly getting worse. The Dealer says that it is the rear differential and he will put a new different fluid in that should solve the problem. He reports that in some cases this solves the problem but if it doesn't they'll replace the differential. Question is, should I push back or not? What if the new fluid kind of works and delays failure of the diff until it becomes my responsibility? Anyone else have experience with this?