Rear axle bearings. To pack or not to pack, that is the question...
Started doing my rear brakes because the seal was leaking. Am replacing the bearings and races too, plus the shoes and flushing out old differential oil and replacing with synthetic.
Went to the auto parts store, picked up the bearings, plus the new lube, and a tube of synthetic grease. The young clerk informed me that he advised NOT to pack the bearings in grease before installing them, to just let the differential oil slosh over to lubricate them.
I am old-school. I have ALWAYS packed a bearing before I place it in, even in the full-floating axle where the differential oil is supposed to keep it lubed.
This young man tried to tell me that the synthetic grease and the fully-synthetic gear oil were not compatible and this would junk out my bearings.
Anybody have an opinion, or have I been doing this wrong for years?

 

good question
I'll let someone more knowing than me answer though I've been told to packe em in the past

 

Not designed for grease, they get oiled by rear end lube.

-Enjoy
fh : )_~

 

If you absolutley have to grease them, just a little bit is all you need. No need to pack them.
What I do is jack up the side you are working on enough that it will hold some oil, and put some in oil the hub while turning it, so the bearings get a good coat, then install the axle shaft with the axle still elevated.

 

What they said - no grease in these bearings, they are lubricated by the oil in the axle. I personally always overfill my truck's axle by a quart to make sure there's always some oil at the bottom of the bearings, but I know many will not agree with me on that. Either way, no grease, just jack the axle ends up one at a time to cause oil to slosh in there and flood the bearings before you drop her down level on the ground and drive off.

 

LCAM, I do the same as you and overfill all of my rearends as well.

 

So I removed the axles and the differential carrier for good since the back half of a 92 F-250 is now a trailer. I cut the axle caps off and bolted them back on the free floating hubs. Do I fill the now empty diff with $25 of 90 weight oil or do I just pack some bearing grease into the wheel bearings?

Since there are no parts to move the gear oil into the axle shafts, will the wheel bearing still get lubed just due to driving around pulling the trailer? I would have to add a lot of oil to get the fluid level up above the fill port since the port is below the bottom of the axle tubes. I can fill through the top of the diff in the sensor port.

I was thinking about how to plug the axle tubes so I could jack up each side and then add a small amount of 90 weight oil just to lube the bearings, but I already sealed the diff cover back in place. Thoughts?

 

Just pack them with grease.

 

Isn't there outer and inner bearings in the hub? How would I pack the inner bearings without removing the hub?

 

Get a rubber expanding freeze plug that fits in the end of the axle tube, drill and tap the flange "cap" for a 1/4" NPT plug, fill with oil to just below the axle tube, enjoy. Make sure to check it every now and then.