How much bearing grease?

caliber60 · 01-02-2003, 09:14 AM

I just replaced the front rotor. How much bearing grease should I fill up the bearing area? I had read other post to pack the grease in the dust cap as well. Is it necessary?

Thanks,

sammyg2 · 01-02-2003, 09:56 AM

You should completely pack the bearings, and that's all. You do not need to pack the cap. It is better to have too much than not enough, but only to a point.

caliber60 · 01-02-2003, 10:05 AM

That's what I did. I repack the outer bearing with bearing packer from Sears. It works great. I did not pack the inner bearing due to removal difficulty.

Superman · 01-02-2003, 10:29 AM

German car makers often specify a fairly large amount of grease in these types of applications. I do too. When I repack CV joints or wheel bearings, I nearly fill the entire area with grease. Grease is cheap.

dhoward · dhoward's Garage

Grease may be cheap, but it makes a heck of a mess the next time you've got anything apart. In order for it to do any good, excess would have to reach it's melting point and flow to where it's needed. Prolly not going to happen in a hub cap.
Take a couple of fingerfulls of grease and smack it into your left palm.(Sounds fun!) Take the bearing in your right hand, and using a scraping motion, cut some of the grease off of your palm, forcing it into the bearing. Rotate slightly. Lather, rinse, repeat. When grease comes out of the other side, you can be sure it's packed sufficiently. If you don't like the squishey feel of grease, use the Sears packer.

Superman · 01-02-2003, 01:39 PM

In the real world, you need more than a shot glass full of grease. Grease does move around in there, otherwise we would only need to pack the bearing, and the rest of the hub could be shiny and clean. The extra grease in there serves to keep the 'grease leve' in there up to the point where the bearing is. In other words, bearings need to be rubbing against a grease dam that is along side the bearing. If that grease dam is not there, then when the pressure in the bearing squeezes grease out, that grease will stay out and the bearing will get dry. The Bentley manual for my old '84 Rabbit advised me to nearly FILL the hub. No problem. That has always been my method.

I have never seen a bad bearing that I had packed.

caliber60 · 01-02-2003, 02:09 PM

"FILL the hub". Very tempting, Should I go ahead and do it? That's not too hard. I wonder what does the factory manual say about it?

Superman · 01-02-2003, 02:17 PM

Well, if you FILL the hub, then you're going to have a problem with the hydraulic pressure pushing the seal out. So, I'm not suggesting a ridiculous amount of grease, but the inside of the hub should be coated with about a half-inch of grease. Just so that both edges of both bearings are dammed with grease. But not enough for the grease to escape the hub through centrifugal pressure, past the seal. Capiche?

I agree with the above remark that grease is filthy. No question about that. Grease is the worst. that is why I use gloves. Latex is okay. Nitrile is better.

dhoward · dhoward's Garage

Quote:

Originally posted by Superman
In the real world,...(snipped)

I have never seen a bad bearing that I had packed.

No doubt.

In the real world, tapered roller bearings have many high-speed, high-load applications (machine tools come to mind...) that don't require a slathering, or "grease dam"(?) - levee or whatever. Please, this is rhetorical, but how does grease in the cap move to the bearing?

Quite honestly, I expected that response. Perhaps you should write a book.

Sheesh.

Fill 'er up!

Superman · 01-02-2003, 02:39 PM

I'm a little tired today, so I hope I have not been irritating. Indeed, I have wondered the same thing. Grease is not going to 'circulate,' so why pack so much in? As near as I can determine, the extra grease is there precisely because grease is not going to recirculate. If it were not there, then the grease would leave the bearing and the bearing would get dry. I also notice that several of the most trusted mechanics I have grilled for information over the years, say that 'factory' amounts of grease or "minimal" amounts of grease, are not enough for the real world. Another possible explanation is is that automotive wheel bearings are out there in freezing cold, we, dirt, heat, etc, adn this is why their industrial brothers and sisters can get away with less grease.

Hey, I just make these up as I go along......

dhoward · dhoward's Garage