Sometimes overlooked by mechanics and restorers is a small vent in the driver’s side rear axle housing approximately 10” from the mounting holding the springs to the housing. This part is necessary to keep internal pressure equal to the outside atmosphere. Thus, as the internal temperature of the differential warms during use, any expanding heated air is vented and no pressure occurs. This saves wheel and pinion seals from leaking.
After many years of use, many vent assemblies were accidentally removed. Now, the small hole that once held the vent assembly is able to take in water. This is certainly not good for the internal differential parts. If the cap is still present, spray under cap with PB Blaster and make sure the cap turns freely. The cap does not come off.
Harold
Rear end Vent
