My 2012 M3W arrived with grease filled bevel box.
I replaced that with redline heavy gear oil after numerous times of filling running and draining to get almost all the black grease out.
The whine (must have straight cut gears in the bevel box) is really getting under my skin so am thinking of injecting some synthetic grease in there to hopefully quieten down that whine.
If it was filled with grease only, so a mixture of grease and heavy gear oil should not be an issue.
Anyone done this or has any opinions?
