Posted by Keith in Washington [24.41.55.59] on Monday, March 17, 2014 at 14:32:08 :
In Reply to: So, to my original question... posted by CSCameron [174.26.45.190] on Monday, March 17, 2014 at 13:47:50 :
It is not needed at all. The seal in the end of the front axle housing separates the diff lube from the knuckle, wheel bearings, spindle and the short axle shaft. The knuckle, short shaft and wheel bearings are lubed by wheel bearing grease that you pack in to those areas. You can usually tell when the inner axle seal has failed when you start weeping thinner grease/diff lube out past the felt knuckle wipers. The outer seal is not needed on the front axle as there is no diff lube in or coming through the spindle. So there is nothing to seal. All you would be doing is spending money for something that is not needed.
The rear axle does not have the inner axle seal at the end of the axle housing. This allows diff lube to get into the spindle. Once into the spindle it will come out of the end of the spindle and into the hub and mix with the bearing grease. The outer seal runs on the outer end of the spindle and blocks the diff lube from mixing with the bearing grease as it comes out of the end of the spindle. The outer seal keeps the diff lube from entering of the hub and therefore from mixing with the bearing grease.