Therefore, expand the under car investigation by putting the vehicle up on the lift, where it is possible to get
a good view of what is going on underneath.
The first problem most likely encountered is an under car fluid leak. If a lot of lube is escaping from the pinion
shaft seal, the drive train noise could be caused by a bad pinion bearing. To confirm the problem, start the engine,
put the transmission in gear and listen at the carrier. If the bearing is noisy, it is necessary to make one of those
difficult judgment calls. If the bearing sounds fine but the pinion seal is still leaking, suggest an on-the-car seal replacement.