Quote:
Originally Posted by Tom Endy
It is my understanding that the seal is a grease seal, not an oil seal. It's purpose is to prevent grease that is pumped in through the grease fitting from traveling down the axle shaft toward the differential.
The design thought is that when grease is pumped in through the grease fitting the seal forces the grease to travel outboard toward the wheel bearing. The large grease seal in the brake drum act as the other end of the trap and forces the grease into the bearing.
This was not one of Henry's better ideas, and a few years after the Model A the grease fitting was discontinued in favor of hand packing the bearing before installation.
I have taken a good many rear axle assemblies apart and found the original CR seal wasted away and with no sign of differential oil in the brakes. In many cases the owner continued to pump grease in through the fitting and the grease then centrifuged around the axle shaft. The more that was pumped in the larger the diameter and the further toward the differential. In many case I found the center section of the axle rusted and devoid of either grease or oil.
If the proper level of oil is maintained in the banjo no oil with reach the seal.
I completely disregard any wear in the axle caused by the seal. The important thing to look for is any cracks at the key slot or damaged threads. The gear end is usually in good shape unless it sat in water and is completely ruined by rust.
Tom Endy
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Tom,
I concur and agree it was not one of Fords great ideas. Hand packing is preferred. I believe the seal was there to help force the grease into the opening between the axle and housing into the hub.... to be captured by the inner seal ( large OD) and just in case any that would come out ( it should never happen) at the outer fiber hub seal under the axle nut washer.
It's just not one I worry about much.... as I said the other issues are much more important and relative.
I concur hand packing a hub bearing is best... Remember the natural shape of the axle housings and drain holes at the carrier end keep the lube where it should be. I've rebuilt a number of Columbias and they have a much higher amount of lube in them into the columbia side housing and I've never had an issue with them either.
Just my own experiences....but as always.. experience is a continuing process! Doing and learning from others...
Larry Shepard