Technical Is it possible to overgrease a bearing?

I have read “ somewhere” that you can get too much grease in a bearing! In my simple mind.... that’s impossible!
In my side business we were experiencing bearing failure. Upon inspection after failure,I found no grease, just dirt, rust, crud, etc.
I then inspected the new bearings that we were replacing the failed bearings with and they had just a little dab of grease, here and there, in the new bearing.
Well , that just wouldn’t do! So I packed the bearing completely full with premium grease! Almost completely eliminated my bearing failure problem!

Any thoughts on this? Was it right? Wrong?





Bones

 

Logically, I agree with you.
From my practical non-pro amateur experience....I agree with you

 

Yeah, don't think you can over grease.

 

If grease gets out of the bearing and contaminates other stuff, then it can be a problem. But in your situation, the more grease, the better

 

Was going to say that, but thought it was reasonably obvious!

 

I have over-greased a posi-lube boat trailer axle and forced the seal out of the hub, but that's a unique situation

 

It's not obvious to the guys who do it.

 

In heavy equipment and forklifts, we use a lot of grease.

Can’t really over grade a bearing besides a sealed or shielded bearing might pop the caps off.
When I replace bearings I remove the seals or caps and pack with grease as you said there’s almost no lube in the new bearing.

only issue I see a lot from over greasing is techs don’t clean the excess grease and it makes a mess or gets clumpy and holds dirt and water.

but too much grease to cause bearing failure
Naw !

 

It all depends on the application. I was involved in a program where we we ruined several fairly large (to us)electric
motors by over-greasing them.
Yes, I realize there are no large electric motors on the average old car, I was just saying you cant make a blanket statement that covers all situations.
Wheel bearing, axle bearings, pilot bearings etc., I've always packed them full.
Good Luck.

 

Recently replaced the u-joints, and was obvious the new u-joints had some grease, but not enough.
So it was obvious I would have to get out the grease gun and add grease after the drive line was installed.

Sigh! if only I would have flipped the u-joint in front so the zirk faced the rear ... I would not need to pull the drive line back out to grease it

 

In my original post, I was referring to damage to the bearing it self. What I read was that too much grease would not allow the balls/ rollers to turn! They would slide instead of roll!

I found that hard to believe, but I’m kinda country! It was from a published source of a reputable company. Can’t remember which at this time, I just remember that point.

The way I see it grease is like money!! You can never have too much!







Bones

 

Not so sure I like some of his methods.
I never hammer on a bearing to remove a seal unless I'm replacing the bearing, and never re-use a seal...they are too cheap not to replace

 

This is why I told my little story about the u-joints .... I think all manufacturers today would skimp on proper grease amount, and leave that to the installer.
Actually this might be a best way to do things.
Proper amount of grease in wheel bearings while sitting on the shelf at the auto parts store .... the grease would be oozing out of the packages and onto the floor.

When I am done installing wheel bearings, I need to wipe the excess off the dust caps and drums.

 

I too, saw a few things I do different on trailer bearings that also happen on car wheel bearing.
The main thing I saw that could cause trouble is finger tightening the nut! I always run down by hand, but then seat it with a pair of channel locks. Not crazy tight,but snug enough to make sure it IS seated.
I also include grease on the outside of the bearing after packing, plus a little in the cap. I know “ they” say not to.... but I do. That little extra in the cap, may melt and run into the outside bearing, should it fail down the road.... and let you make it home.
The other thing I do is tighten the bearings a little more than most. I do not want any play in my bearing. That play causes impact on the bearings. We learned this many years ago on the ranch. With slow moving wheels. I know about the heat and expansion, stuff. I just lean toward the tighter side of those specs.
Also, I try to be a little cleaner with my bearings and seals.






Bones

 

@Boneyard51

what I find at work is to use the correct grease for the application

mast , steering components, king pins, chassis pivot points get a thick moly grease.

wheel bearings get wheel bearing grease

electric motor bearings get a light grease ( can’t remember the type right now)

the wrong grease in the wrong application can cause premature failure or other components to fail.

as @Rex_A_Lott sstated I have seen high rpm bearings fail due to wrong lube or other parts fail due to contamination.

so a blanket statement over greasing is fine is not correct for everything, but in most cases more grease is better then not enough.

 

My I/R air compressor is very specific about when and how much to grease the electric motor. In this case less may be better.

 

I was able to attend a bearing seminar at Timken, in Union, S.C., and I learned a good bit about fits, clearances installation methods etc. This was not at the production factory, but at a bearing rebuilding facility. They got back bearings from all over the world to be rebuilt, the one they were working on that day had been shipped in from China. They would regrind the race, then grind new rollers to fit and then reassemble. This was a tapered roller bearing, just like your front wheel bearings. They guy said it wasnt usually cost effective to do that procedure on any thing with a shaft diameter smaller than 20 inches, and went way up from there. They moved the bearing components around with cranes.
Amazing facility, and yes I know what you mean by being an old country boy.

 

I would think this may lead to bearing failure IMHO, and maybe that should be discussed?

Myself, I was taught to tighten the bearings down to make sure they were seated. Then back the nut off maybe 1/4 turn to loosen them up. Whatever it took to get the cotter key in, might be a 1/2 turn. but a loose free rolling bearing.
The roller bearings need freedom to move.
I think the looser they are, the longer they would last
The ultimate test to me is, with the wheel installed, can I rock the wheel back and forth and get bearing movement?
If there is any movement, then it is to loose. It needs to be tighter.

If I can loosen the bearing, give it lots of freedom, yet when the tire/wheel is installed and I cant grab it and rock it from side to side and get no play in the bearings ... to me that is just right.

I would certainly think, A bearing adjusted to tight would grind itself to a quick death.

Remember though, I am just a dumb ol carpenter

 

I was in the bussiness of building automated equipment. In most cases no such thing as too much in slow moving parts, pillow blocks, ect. Thats because most people don't grease till it's too late. High speed bearings may overheat and ouze grease out if over greased. Automotive: fill the rollers, a little extra on outside, good to go. The correct grease for the job is most important, ie, high temp for disc brakes. Don't over tighted, causes flat spots. Not too loose, causes flat spots.

 

This is a video I saw after watching HRP's video.This is from Timken

 

It's for trailer bearings, but I would think it'd be for front wheels on cars also. Shows how much to tighten and the correct tools

 

If you monitor a bearing after it is greased, the temperature of the bearing will increase due to the resistance caused by the grease as the bearing pushes thru it. It then decreases as the rolling elements channel out the grease.
The resistance of the grease can cause the rolling element to slide so causing small imperfections to the surface of the race and the rolling element at the point of contact.
The grease is a combination of soap and oil. (Lithium predominantly but Polyurea is used in the grease for electric motors or high speed applications. The heat helps bleed the oil out of the soap.... it is the oil that is the lubricant.
Bearing failure is usually not from over lubrication.

Drive it until the wheels fall off....

 

Los-control, that’s real close to how I adjust bearing. I try to get no play, very little pre- load.
I never give heavy pre- load.
I have seen some mechanics adjust the bearing so that you can actually “ wiggle” the wheel a little. I don’t do that. I guess I’m fairly close, I have no known failures with my method.







Bones

 

Boneyard51 I think you are doing everything just right.
Proper amount of oozing grease, and pre-load.

The only other thing, we do not know what the application is.
If you are getting premature bearing failure, there is a break down in the process somewhere.
I once had a 1967 truck and went through 3 alternators, because the re-builders were installing the front bearing backwards.
Possible in your situation that the bearings are not correct or going in wrong?

 

I got really fussy about leaving no grease in my dust caps a while back, then discovered that water had weeped in and they had actually started to rust a little. I pulled all of them off, and put some in them to act as a seal of sorts. I personally adjust them to the point of no free play, and then go just tight enough from that point to get the cotter pins in. I will also admit to using no.2 grease on them, which we also use everywhere on a full-size drilling rig, and have never had a wheel bearing failure. As to the original question, I don't believe you can overgrease anything on a motor vehicle (engine vehicle to some) unless, as previously stated, you blow out a seal, or get grease piled up in your brake components. Maybe in an environment where things come immediately up to speed, like a 100hp electric motor, it might be an issue, but on a car, no.

 

Yes

What happens to the excess grease and where it migrated to can be of concern.

For example - if the application is an inner wheel bearing on a trailer axle spindle - the excess grease can enter the mechanical area of the backing plate on electric brakes.

If grease gets to the brake shoes - no brakes.

EZ Lube spindles have a zerc on the end along with a removable rubber plug to access the zerc.

A lot of folks pump too much grease into that zerc.


Jim

 

On every trailer I've ever bought new or used I pull the bearings and grease them up. I've seen new trailer bearings with the clear grease wtf, but I had two broken races over the years. I use plenty of synthetic grease and have never had a failure.

 

Funny you mention bearing races.

I just replaced a brake drum on my enclosed car hauler trailer because the outer bearing race was loose and had been spinning - burned up the bearing.

Brake drum was stamped “ Made in America “ into the steel.

It was less than two years old - on the driver side - ovalled out casting for the race I guess.


Jim