I had one issue with my brothers Olds rear end.. much like a dana.. the axle tubes were welded to the case but at Norwalk the one tube broke the weld free and that tube would rotate in the housing.. at first I didnt figure out that the tube was rotating but 1 wheelie bar was way lower than the other.. the welds were a previous owner and didnt hold... I pulled the diff and zeroed it up again and re-welded with nickle rod and its been fine since.... this was in his 8 sec nostalgia altered