How could I define that?My 87 325is race car diff is still going on with 440whp/400wtq and 255 slick tires.On the other hand I heard for a 4 E70 diff failures last week alone.My friend's 08 4.8i has the diff removed yesterday and the shop owners says that one of the bearing races has moved somehow and there is a complete mess inside.Likely nothing is reusable.