revor said:Do you mean it comes loose after a while or doesn't tighten fully down? If it never gets tight I'd check the threads and make sure the correct washer is in place.. On the other hand if it keeps coming loose I'd make sure I was getting all I could on it to torque it.. Block the wheels, in gear (any) parking brake on.. etc.. Check a Manual, some diesels require a lock washer although I don't recall one on any Rover motor I've ever seen..