Front Hub Grease

[Dallas]

Interesting,
I learn something new every day! LOL.
My old Mack (1941 A-40) required no extra grease in the hub neither did my Diamond Reo or my 1968 KW.
I'll be digging out the PD-4103 manual tomorrow and see what it has to say about them.

I'll see if I still have a copy of the PD4104 manual also to check and see if they changed anything.

I have not heard of thin coating of grease method, but anything is possible. Here is what my old Freightliner Manual says.

"Pack the bearings with a pressure packer if possible. If a packer is not available, pack them by hand, forcing the grease into the cavities between the rollers and the cage from the large end of the cone. Pack the hub between the two bearings with grease to the level of the cups smallest diameter. If the hubs contain oil it is still necessary to pack the bearings with grease".

This means pack the entire circumference of the hub with grease, above the level that the bearings turn, so that if/when the grease gets hot it cannot escape the rolling bearing surfaces. The outside bearing normally sets inside the smallest cup, so the top lip above the rollers would be the proper level to fill the hub for a bearing running in grease.

[Fredward]

you're all pretty much confirming what I expected regarding packed greased bearings. And mine have been packed recently and the grease is nice and red.

The remaining question is: The manual shows a lubricant level for the front bearings yet it specifies grease. I don't understand how you could ever have a "Grease Level" in a packed wheel bearing. Other than it appears that filling the cavity to some degree would make sense. Maybe I have the wrong version of the manual for my 5-C.

[Dallas]

Some MCI's used wet hubs and some used greased hubs, depending on how they were spec'd from the factory.. I would expect that if the manual gives a level, it's for wet hubs.

[gus]

"Thin coat" was probably not the right way to say it, what I was trying to say was not to pack the hub full of grease. If you do it will leak when hot.

On the other hand, I never packed so much in that it came to the bearing smaller diameter either, that is a lot of grease.

My theory is that if there is a reasonable coat of grease on the hub and cover no grease will migrate from the bearings to the hub. That will happen if there is any bare metal in the hub, thus the reason to add some grease to the hub surface.

I use that system unless my manual says otherwise, to each his own.

[DaveG]

I think we finally got this one! Good job everyone!