rear wheel bearing lubrication

[wallytoo]

i've got a full-floating rear axle (1.5 ton 2-speed). the manual states that the rear wheel bearings should be packed with wheel bearing grease. i'm curious if anybody has any input on that. i ask because as far as i can determine, there are no axle shaft seals - thus, the gear lube for the differential is not excluded from the hub/bearing units. in my past other vehicle experiences, if there isn't an inner shaft seal, then the bearings aren't packed with grease, instead, they rely on the gear lube from the diff. it seems that packing them with grease would ultimately lead to contamination of the differential.

and i thought replacing the wheel cylinder was going to be a quick job.

wally

[Merle Coggins]

I just looked through my manual too. I see what you mean, but aparently they felt that the axle oil wasn't sufficient for the wheel bearings, so they have them packed with grease. I guess I would follow the manual and grease pack them to be on the safe side. If the axle oil does get into the bearings and breaks down the grease, I don't believe it would cause any serious problems.

Merle

[MBF]

I'm speaking from experience here (not sure what that is worth) but on my 1 ton w full floating rear I have always packed the bearings when apart as told to by a friend of mine that is a truck mechanic. The logicfor this is that the gear oil from the diff has to work its way through the outer bearing before it gets to the inner one. This process just prevents premature wheel bearing failure. I know for a fact that this can happen-a neighbor once did a rear brake job on a Winnebago with a full floating rear and didn't pack the bearings after reassembling it. Even though the rear was full of gear oil when he was done-he made it less than 2 miles down the road before both bearings on both sides disintigrated. A wheel lift tow charge, 2 sets of bearing and seals later along with a Saturday spent cleaning up the axle faces was the result. He repacked them the 2nd time around. Mike

[wallytoo]

thank you for the input. i will go about packing them. i appreciate the help.

wally

[David Muma]

I think if you look carefully at the parts diagram you will see that there is a seal that separate the diff lube from the greased bearings on the full floating axle. I know that my 1 ton is so equipped.

[MBF]

Its only been a short while since I had mine apart, but I thought the outer seal was to keep it from leaking out of the axle end-and to divert the gear oil from the end of the axle to the bearings mmmmmmmmmmmm not real sure. I remember that there were 2 different type seals, and kinda recall one was flanged?.? I think I have the NAPA or industry part numbers written down in my maintenance records for my 1 ton if you need them. Man-I can't believe I don't remember what that looked like and I just replace my rear lug bolts earlier this Winter! Mike

[wallytoo]

there is no seal to keep the diff lube away from the wheel bearings. the only seal is a gasket on the axle flange (to keep the oil from leaking outside of the hub assembly). there is an inner seal outside of the inner wheel bearing. again, this is to retain whatever fluid/grease is in the hub, and to prevent outside dirt/contaminants from getting into the hub, not to prevent diff lube from reaching the bearings. there is no machined surface on the axle shaft (other than the flange - as noted), thus there isn't any interior seal.

i've got the bearing numbers and the inner bearing seal number (timken 455249).

wally

[wallytoo]

fedex delivered the inner bearing seals today (timken - part # in previous post). repacked the bearings with grease, installed the hub/drum assembly, tightened the spindle nuts/lock rings, slid the axle shaft in and attached the nuts/washers. put the first wheel on, and attached the inner lug nuts. put the second wheel on, and attached the outer lug nuts. dropped it down, and started it up.

first time it had been started in 3 weeks, and it started quickly (it was 17* here today). the new rear wheel cylinder works, and the brakes are almost up. just need to bleed them tomorrow.

i used rtv-blue for the axle flange, since i tore the paper gasket on removal. seems to be keeping the oil in. so, what i thought was going to be an afternoon's work turned in to two weeks of work. but, it's done.

[MBF]

Those 5 minute jobs can sometimes be a bear, and then something you thought would be a challenge turns out easier than expected. Glad you got her back together. Enjoy the first ride-she must be anxious too if she started good in 17 degree weather! Mike

[wallytoo]

yeah, the goal is to have it officially on the road by the end of next week. just a few more wiring issues to clean up. i'm going to register it as an antique vehicle. fortunately, nh has very few restrictions with such a registration. it just has to pass a safety inspection, and it will.

wally