How much is too much or too little wheel bearing grease?

[Jake733]

I’ve made a start on repacking the grease in my twin axle ‘electric brakes’ wheel bearings. I’ve finished two wheels and will finish the other two tomorrow. Having bought a grease packing tool, I’ve made sure that the new grease has forced the old darker grease out of the bearings. Those two are now reassembled. I noticed whilst doing the job that one set of bearings had quite a lot of grease in the void between the two bearings as well as in the bearings themselves. There was quite a bit in the metal seal cap too, completely covering the castle nut. The other wheel had grease in both bearings but the void between them was empty. The grease over the castle nut on that one was a small amount and the grease cap was empty and dry. Here’s my question: Which one is the most desirable and which one is risky, if at all? Races in all were perfect and all bearings were as good as new. Both hubs were bone dry, so neither have had leakage problems.

[BRinSCupstate]

I would think some in between the bearings and under cap would be best. If dry in between and under cap, I would be concerned the grease would eventually be pushed out of bearing.
I’m interested to read other comments. Doesn’t sound like you have them, but the EZ lube (lots of concerns, by other members), if done correctly, would pack them full. I think full is too much.

[handyman58]

I am also ready to pack bearings on my TT. When I was a mechanic back in the days with packable bearings I would put grease in between the bearings in the hub up against the bearings. My thought was it would help if any grease would push out of the bearings. Probably would never happen but I thought it was a little insurance and made me believe it was a better job completed.

[NavyLCDR]

I don't see any need for grease under the metal/plastic cap and outside the castle nut. That sounds like an EZ lube job that somebody did not clean up after.

[Bama Rambler]

Originally Posted by Jake733

... I noticed whilst doing the job that one set of bearings had quite a lot of grease in the void between the two bearings as well as in the bearings themselves. There was quite a bit in the metal seal cap too, completely covering the castle nut. The other wheel had grease in both bearings but the void between them was empty. The grease over the castle nut on that one was a small amount and the grease cap was empty and dry.

Here’s my question: Which one is the most desirable and which one is risky, if at all?

Technically as long as all the voids between the rollers are full and there's a little extra around the bearing, that's plenty of grease. While I like a little extra in the hub cavity, it's not required as long as the bearings are full.

[Iwannacamp]

I think Bama is correct. The only amount required is in the bearings. Grease works as I understand) by weeping oil to lubricate. I don’t think you can get too much as the grease through hubs fill the cavity as well as bearing buddy type set ups.
Fwiw when I did mine I packed all I could in the void with synthetic wheel bearing grease, Timken bearings and new seals.

[SailorSam20500]

I was just at the International Rally. On request, the guys from Dexter took a look at my rig. They repacked 2 of my wheels. Their procedure:


Remove the seal and pull the bearings.
Clean the bearings with some cleaner (brake cleaner spray?)
Using a packer, grease the bearings.
Replace inner bearing and add seal (seal only goes on until outer side is flush with wheel - don't push in farther).
Push a finger load of grease into the center of the wheel.
Reinsert outer bearing and remount wheel.
Mount d-washer.
Tighten wheel castle nut with wrench - tight!
Loosen castle nut and adjust to finger tight.
Apply cage or insert cotter pin.
Mount cap

They did not put any grease on the castle nut.


YMMV

[Bob K4TAX]

When repacking wheel bearings, the bearings must be thoroughly cleaned first.

Just using a packing took and squirting in more grease will not allow one to thoroughly inspect the bearings.

I've got a packing tool but I'll revert to the hand packing method. Any excess grease in my hand will be applied to the races and spindles. Then a single shop towel is all that is needed to wipe clean my hands.

Bob

[D W]

Originally Posted by Bama Rambler

Technically as long as all the voids between the rollers are full and there's a little extra around the bearing, that's plenty of grease. While I like a little extra in the hub cavity, it's not required as long as the bearings are full.

X2. There is no plausible reason to pack the hub full of grease, only the bearings. Wheel bearing grease has a minimum drop point of 300°F, meaning that the grease is not going to "flow" at temps below 300°F. If your bearings or hubs reach that temperature, it's all over. Doesn't matter how much grease is packed in there.

[Larry-NC]

Originally Posted by NavyLCDR

I don't see any need for grease under the metal/plastic cap and outside the castle nut. That sounds like an EZ lube job that somebody did not clean up after.

Some of us old-timers would put some grease in the hub in the area between bearing races and some in the "hub cap" under the belief that it would prevent moisture condensation at the metal surfaces. Maybe displacing all the air means displacing the water vapor, too.

That's what I was taught when I worked in the garage, summers of '63 and '64. I often (maybe always) saw front-wheel brake drum hubs packed completely full--you had to take them off to work on the drum brakes.

Titan Mike will probably chime in here, with similar experiences.

[TitanMike]

Originally Posted by Larry-NC

Some of us old-timers would put some grease in the hub in the area between bearing races and some in the "hub cap" under the belief that it would prevent moisture condensation at the metal surfaces. Maybe displacing all the air means displacing the water vapor, too.

That's what I was taught when I worked in the garage, summers of '63 and '64. I often (maybe always) saw front-wheel brake drum hubs packed completely full--you had to take them off to work on the drum brakes.

Titan Mike will probably chime in here, with similar experiences.

I started a couple years before your "garage days" and just about every mechanic back then (and even now) had their own ideas of what should be done. Wasn't really much info provided by factories back then to other than their dealership shops and even then the mechanics "all knew better".

A lot has changed since those days when leather and felt seals were common in hubs. Ditto for wheel bearing greases that often had the consistency of road tar mixed with flour.

I rarely saw hubs completely filled with grease as back in those days the internal space in the hub was a lot more than it is today. Usually the mechanics just smeared some grease on the inner race before installing the "packed" inner cone assy and seal. Same on front race/cone.

Out here on the Pacific Coast it was common or one to smear a thin coat of grease on the spindle, especially where the seal contacted the spindle, to prevent rust/corrosion. Most of the "dust covers" were galvanized so rust wasn't a real problem.

The biggest issue over the years is that when manufacturers (cars and bearings) upgraded their products and maintenance procedures the mechanics (Pro's and shade-tree alike) hung onto "the way we always used to do it" methods and each insisted they were the only ones doing it right.

Nothing in that respect has changed


When it comes to filling hubs with grease, it's not necessary but it also causes no problems. If a seal leaks chances are it was damaged when installed, damaged during an inspection (and not replaced) or the bearings weren't adjusted properly allowing premature wear.

[Jake733]

Well l, I’m certainly glad I asked that one. Thanks for all the interest and answers. When you do the job and put everything back together, of course it’s all out of sight from then on. Puts the self doubt quotient up a bit, wondering what’s happening inside. We’re off with the rv tomorrow and I feel a lot better that I’ve done things right. I’ll probably stop somewhere along the way and take a temperature reading on the hubs with my digital thermometer. Thanks again.

[frozen]

Being on the side that prefers packing by hand, I've always considered filling the cavity between the inner and outer bearings a waste of grease; it doesn't migrate to the bearings--just sits there doing nothing. And I've wondered how much of that grease actually moves when grease is pumped in through zerks.

I learned an aid to hand-packing; I bought a grease needle for my grease gun. It simply screws onto the outlet. After removing and cleaning the bearings, I inject grease between all the rollers using the needle. I also squeeze grease in by hand to complete the lubrication. I smear a film onto the races and the space between bearings. One tube of quality grease is adequate for all 4 wheels.

[5picker]

I'm in the camp of if the bearings are properly packed and grease is smeared in the races before installing the bearings, anything more than that (in the hub area between the bearings and the cap area) is wasted grease.

Do those areas get filled when using the EZ-Lube option?... yes... but that's by design to push the old grease out of the bearings and fill them with new grease, not because those voids need to have grease in them.

[jcrevs]

I bought one of these bearing packers, it works pretty good.

[BRinSCupstate]

Originally Posted by jcrevs

I bought one of these bearing packers, it works pretty good.

That's pretty fancy there! I think I'll put that on my camper list! Thanks for sharing.

[REL]

Less than this is better. 😳

[BRinSCupstate]

REL, I hope that wasn't yours. I pushed a seal out on my boat trailer once.

[IamProStreet]

Originally Posted by REL

Less than this is better. [emoji15]

That looks a little light on the grease to me! [emoji1787]

[Robusto]

Ha Ha Ha! Gotta love that REL! Someone buys grease by the 55 Gallon drum huh?


I'm with DW, Frozen, and 5Picker on not filling the hub between the bearings. Like someone said, that grease isn't going anywhere. As a matter of fact, you load the hub up with it and it creates drag on the wheel going around. Don't believe me, fill up the hub, then with the wheel off the ground give her a spin and see how many revolutions it makes. Then clean out most of it, just leaving the bearings packed and having removed almost all from the inner space and try the spin again. Bet you see that wheel go around quite a few more revolutions...a lot less drag.


What's more important I believe is the torque on the nut snugging up the bearings---too tight and they'll more likely overheat, too loose and they'll wear prematurely. Tighten up the nut until there is some "stiffness" to rotate the wheel, like where it only rotates about once. Then back off the nut slightly, progressively, until it spins 'freely', at which point if you grab the wheel/tire with right and left hands opposite each other and push/pull oppositely, you should hear only a slight 'click', barely discernible, and possibly not. At that point if the wheel spins quite freely you should be good. If the cotter pin won't go thru, then typically back off slightly until it does, or you could also try tighter, as long as the wheel/tire spins freely. I've used this method for fifty years plus on cars, trucks, trailers, and never had a failure.