Info needed: F30 grease seals ?

[rob love]

Phil

Are you talking about the outer wheel seal? That is to say,the one that is sandwiched between the two adjusting nuts? Yes, that one you may get away without for a spell, but personally I prefer them installed.

Or are you talking about the inner wheel seal as illustrated in the second post? That would be very unsafe to be running without that installed. When the grease warms up, it can throw into the brakes causing as much problem the oil would. Overpacking the hub is not ideal either as it retains heat. Just enough grease to lubricate the bearings and coat all the surfaces is how I run.

[Phil Waterman]

Hi Rob

I was speaking of one in Lynn's picture but the outer seals under the wheel axle shafts nut are missing from that truck (Pattern 12 C60L ) as there was no seal lip was left.

As to over packing wheel bearings, I agree, you and I have both seen wheel hubs were the entire hub between the bearings was packed solid with grease, which is an invatation for grease getting where it should not. My extremely well packed is being sure to fill the spaces between all the rollers.

It really just boils how steep a cross slope you want to drive or park the truck on. Sure would not want do any mud bogging or deep water fording with out the seal in the picture.

At the time I found the seal sitting on the shelf I had been working on all three CMPs so I didn't have a clue which truck or which wheel it was missing from. Figured that a little driving and it would become evident, it never did. Wasn't until five or so years later, when doing preventive maintenance that I found which wheel.

Cheers Phil

[Lynn Eades]

Phil, I certainly wouldn't run without the inner hub seal, and i wouldn't take a chance on leaving the outer hub seal out. That to me is my second line of defence. It is there to keep the diff oil from mixing with the grease in the wheel bearings. The oil can walk along the axles. It doesn't have to be used at steep angles to get oil to the hubs.
The idea is to fully pack the wheel bearings, but not to pack the hub cavity.
I always work the grease in from the big end of the rollers until is comes through at the small end (of each cone)
I give the hub inner a generous wipe of grease all over the steel surface,(this is practicing paranoia ) but leave the cavity otherwise empty. ( the cups and seal track get coated as well, of course)

Back around WWII and earlier the grease was not as we know it today.(I think Moly was a WWII discovery) It used to melt and run like oil in the hub and the procedure was to partly fill the hub. The grease melted and ran into the bearings) (using the old grease without your inner hub seal (BB-1175-c) would have filled your brakes with grease on the first run)
Nowadays the grease is so much better that some car wheel bearings come factory packed and when they deteriorate they are renewed.
The high melting point moly (molybdenum di sulphide) greases don't melt. It requires only a small quantity to adequately lube the bearings. (the rolling action never completely rolls the lube away)
When I was an apprentice, (early 70s) front wheel bearings in a car were generally re packed annually or at about 12,000 miles (20,000 km) Today I would think many factory sealed (factory preloaded) wheel bearings are good for a million km.