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MYBAD79
06-08-2008, 01:01 AM
How important is "packing" wheel bearings ? I just installed new bearings and greased them without a packing tool.... .... ????????

SmokinBBC
06-08-2008, 01:32 AM
I pack mine the good old fashion way....grease in the palm.

redvetracr
06-08-2008, 02:16 AM
I pack mine the good old fashion way....grease in the palm.

me too....

MYBAD79
06-08-2008, 02:23 AM
Thanks guys, now I feel better...... I'm sure I put enough grease in there for the next 100K miles.... :thumbs:

Twin_Turbo
06-08-2008, 07:45 AM
Me too, just did a bunch yesterday. It's a messy job and takes longer than with the tool but you'll know it's done right.

Karsten, just putting grease in the cavity won't do, you have to physically force the grease between the rollers. You do this by putting grease in a cupped hand and then pulling the bearing through on it's side so the grease gets under the cage, do this all round and roll it, the grease will go in and you can add more. Do this until you're satisfied that you packed them properly.

If you do not do this the bearings may run too dry and thay will burn up.

Too much grease will blow out the bearing seals!

MYBAD79
06-08-2008, 11:23 AM
Hey Marck, I did not just throw the dry bearing in there...;)

I did grease the rollers and pushed the grease between and behind the rollers, I just didn't use the fancy packing tool.

The cavity between the rollers and the inner race is completely filled with grease if you believe the advertisements for the packing tools - maybe I did not cover 100% of that cavity but close....

Twin_Turbo
06-08-2008, 11:27 AM
So you packed them by hand like the rest of us :D

Yellow73SB
06-08-2008, 01:28 PM
A youtube video

[Only registered and activated users can see links]

turtlevette
06-08-2008, 09:10 PM
Me too, just did a bunch yesterday. It's a messy job and takes longer than with the tool but you'll know it's done right.

Karsten, just putting grease in the cavity won't do, you have to physically force the grease between the rollers. You do this by putting grease in a cupped hand and then pulling the bearing through on it's side so the grease gets under the cage, do this all round and roll it, the grease will go in and you can add more. Do this until you're satisfied that you packed them properly.

If you do not do this the bearings may run too dry and thay will burn up.

Too much grease will blow out the bearing seals!


i'm wondering if this is something else that is way overblown. When the grease gets hot its going to move around like oil and slump down and submerge the lower part of the bearing as it rotates. I almost completley fill the entire cavity. That amount of grease will aid in cooling.

Twin_Turbo
06-08-2008, 10:02 PM
Yes, when the grease reaches it's drop point the gel liqiufies. This means it also expands.

if you pack your grease cavity full of grease it will blow past the seal, compromisig the seal. In a drum brake application you also will get grease on the brake shoes, having disastrous effect on braking.

The liqiufied grease will not slump down, it slings to the bearings and the spinning shaft and will get thrown around violently. It will most certainly not settle when the wheel is turning.


BTW, just did a search, common drop point is around 180*C

turtlevette
06-08-2008, 10:23 PM
Yes, when the grease reaches it's drop point the gel liqiufies. This means it also expands.

if you pack your grease cavity full of grease it will blow past the seal, compromisig the seal. In a drum brake application you also will get grease on the brake shoes, having disastrous effect on braking.

The liqiufied grease will not slump down, it slings to the bearings and the spinning shaft and will get thrown around violently. It will most certainly not settle when the wheel is turning.


BTW, just did a search, common drop point is around 180*C

i pack it almost full there are a few small air pockets. Its actually the air that expands and forces the grease into the outer bearing. Grease does not expand that much. I see it as insurance if a bearing fails there will be enough grease in there to prevent a catastrophic failure such as a broken or twisted off spindle.

The point is the grease will liquify and sling into the bearing. When you come to a stop it will slump and "pack" itself into the bearing if you have enough grease in there. Too little grease and this process will not happen. Most failures are because of too little grease or dried out grease.

a lot of c3ers will never get their rotors up to 180 C 356 F certainly not on the way to the show n' shine.

MYBAD79
06-09-2008, 02:27 AM
I used "green grease" ... that stuff is a synthetic waterproof grease and recommended by the two guys garage :smash::thumbs::smash:

On the cartridge it says it's good for 550F.

The Valvoline synthetic blend grease is good for 450F, the other stuff that I had sitting on my shelf is LiquiMoly and that didn't have a readable label.

BRUTAL64
06-10-2008, 07:06 PM
I pack mine the good old fashion way....grease in the palm.

Thats the way I do it. :noworry:

Twin_Turbo
06-10-2008, 08:29 PM
Yes, when the grease reaches it's drop point the gel liqiufies. This means it also expands.

if you pack your grease cavity full of grease it will blow past the seal, compromisig the seal. In a drum brake application you also will get grease on the brake shoes, having disastrous effect on braking.

The liqiufied grease will not slump down, it slings to the bearings and the spinning shaft and will get thrown around violently. It will most certainly not settle when the wheel is turning.


BTW, just did a search, common drop point is around 180*C

i pack it almost full there are a few small air pockets. Its actually the air that expands and forces the grease into the outer bearing. Grease does not expand that much. I see it as insurance if a bearing fails there will be enough grease in there to prevent a catastrophic failure such as a broken or twisted off spindle.

The point is the grease will liquify and sling into the bearing. When you come to a stop it will slump and "pack" itself into the bearing if you have enough grease in there. Too little grease and this process will not happen. Most failures are because of too little grease or dried out grease.

a lot of c3ers will never get their rotors up to 180 C 356 F certainly not on the way to the show n' shine.


Look up NP-7502

Also air is compressible, grease is not, grease heat expands considerably, some have higher thermal expansion coefficients than air (at the same temp)

Check a sealed greased for life bearing, take off the dust seal and check how much grease is actually in there. Very little, not even 1/3rd packed full.

turtlevette
06-11-2008, 02:48 AM
grease heat expands considerably, some have higher thermal expansion coefficients than air (at the same temp)


Now you really don't believe that do you?

Twin_Turbo
06-11-2008, 09:10 AM
Of course I do not (it's usually in the 0.75x10^-3 range so about 1/5th of that of air), I was attempting to send you on a wild goose chase. See, it doesn't matter if I try to bring in some factual info, you keep on disagreeing so I figured I'd come up with some complete BS, maybe you would accept that. I even would have expected you to catch onto this reply a lot sooner. Have you been google-ing? :D

Your only reasoning is that you jerry rigged something and you put on a bunch of miles and ergo, therefore it must be proper engineering/mechanics

Q.E.D.

But in reality the air tries to expand it just compresses and the inside pressure is raised. With the grease (liquified even) you get a hydraulic effect which will instantly try to relieve through the weakest part, blowing the seal.

Did you look up that premature bearing failure report for electric motors in nuclear control rod installations?

But as always, there's no convincing you so there's no need to bother trying to.

turtlevette
06-11-2008, 02:58 PM
Did you look up that premature bearing failure report for electric motors in nuclear control rod installations?

But as always, there's no convincing you so there's no need to bother trying to.


yes, The grease shield/seal was being pushed out and grease was getting into the air gap on the motor. C3 bearings are low tech. Actually if you think about it. Its actually fun to think for yourself. Give it a whirl. The grease will push out through the rollers on the outer bearing first and into the dust cap. Then if the dust cap fills solid then the grease will push out the inner seal.

On the back there are seals on both sides so it will push past the seal. I've never seen one blow out. The seal is plyable enough to let the grease bypass under pressure. What's the downside to a little grease pushing out past the seals......not much. In the motor it caused insulation failure. Comparing apples to oranges or wooden shoes to running shoes.

The point i keep trying to make over and over is we can accept the standard line on things and move on without thinking about it or we can examine WHY. Its much more fun to do the latter and i would think what this forum is about.

Twin_Turbo
06-11-2008, 03:00 PM
If you get grease past the seals in the rear it will directly affect your parking brake, here that's an instant failure.it's hard enough to get them operating to a standard where they are not a reason for failure during a test.

Dirtbuster1
06-11-2008, 03:02 PM
Over greasing the bearings is just as bad as under greasing them. Over greasing will cause excessive heat on the bearing until it leaks eventally leaks out of the seals. Mechanics that use to work with would pump bearings full of grease until they leaked out of the seal. That was the only way they knew grease was actually getting to the bearing. The next day operations would call complaining about the bearings were running hot and suspected there might be bearing problems. There would be a pile of grease looking like a turd sitting below the housings. Better safe than sorry!:lol:

big2bird
06-11-2008, 03:07 PM
The point i keep trying to make over and over is we can accept the standard line on things and move on without thinking about it or we can examine WHY. Its much more fun to do the latter and i would think what this forum is about.

Well put. And THAT is when you are at your finest. IF, you can refrain from personal anecdotes. :drink:Fair enough?:huh:

big2bird
06-11-2008, 03:09 PM
Over greasing the bearings is just as bad as under greasing them. Over greasing will cause excessive heat on the bearing until it leaks eventally leaks out of the seals. Mechanics that use to work with would pump bearings full of grease until they leaked out of the seal. That was the only way they knew grease was actually getting to the bearing. The next day operations would call complaining about the bearings were running hot and suspected there might be bearing problems. There would be a pile of grease looking like a turd sitting below the housings. Better safe than sorry!:lol:

Sometimes REAL WORLD experience TRUMPS mind boggling theory.;)

turtlevette
06-11-2008, 05:22 PM
Over greasing will cause excessive heat on the bearing until it leaks eventally leaks out of the seals.

How to you come to that conclusion?

The bearing will only overheat if all the grease leaks out first.

turtlevette
06-11-2008, 05:42 PM
Over greasing the bearings is just as bad as under greasing them. Over greasing will cause excessive heat on the bearing until it leaks eventally leaks out of the seals. Mechanics that use to work with would pump bearings full of grease until they leaked out of the seal. That was the only way they knew grease was actually getting to the bearing. The next day operations would call complaining about the bearings were running hot and suspected there might be bearing problems. There would be a pile of grease looking like a turd sitting below the housings. Better safe than sorry!:lol:

Sometimes REAL WORLD experience TRUMPS mind boggling theory.;)

first you say don't use personal experience then someone uses an example of electric motors and YOU say that's a great proof of "real world experience". The grease seal on a motor is nothing like the low tech rubber seal on the C3.

Come on guys. Are we going to have a C3 site based on science or old wives tales? As far as i'm concerned if someone is parroting something they've seen or read without being able to explain the WHY.....its an old wives tale.

Now. Lets think about this. There is no vent on the rear bearing housing. When the air space in there goes from ambient to 400 F there will be a significant pressure on the seal no matter how much grease is in there. The seal is going to have to burp to relieve the pressure.\

If a hole could be drilled in the bearing housing and an appropriate vent installed that would allow us to pack it full of grease without the worry of seal leakage, that might be a good improvement.

I'm not that concerned about grease leaking past the outer seal and slinging on the drum. I pull the rotor often enough and clean it up with brake clean. If a vent was drilled on top grease could piss out in a controlled way and in a location where it wouldn't affect anything, you could just periodically wipe it down with a paper towell.

69427
06-11-2008, 05:56 PM
.................. As far as i'm concerned if someone is parroting something they've seen or read without being able to explain the WHY.....its an old wives tale.

Shit..... I wake up miserable after the visit to the dentist yesterday. Now I'm finding myself agreeing with TV. I don't like the way this day is trending here. LOL

stinger12
06-11-2008, 06:20 PM
So have any of you boys attempted to even call a bearing company, and asked them which is right and which is wrong? You know they do have bearing specialists that work for them - they'll give you a straight answer.

MYBAD79
06-11-2008, 06:50 PM
Front wheel bearings: the greas leaks either into the dust cap or into the cavity between seal and bearing.

The volume of these two cavities is larger than the amount of grease you can put on the bearing - how do you think you could overgrease it ?

You cant insert more grease that what fits between the roller, when it's full it's full, the grease will squeeze out while you install it... Even IF someone dumped half a pound of grease on the race and then install the bearing the grease will squeeze into the huge cavity between the two bearings (which I should have taken a photo of, I had a lot of grease there...)

Twin_Turbo
06-11-2008, 06:59 PM
I think the point that is overlooked here is that the oil separation or liquidizing of the grease is essential for lubrication, cooling. it's what provides the lubracation film. Just the grease itself does not. The bearing is packed with grease, the rest in the cavity is just additional grease to supply the ebaring with grease that's lost when rotating, sort of like the oil sump in your engine is a buffer.

big2bird
06-11-2008, 07:30 PM
.................. As far as i'm concerned if someone is parroting something they've seen or read without being able to explain the WHY.....its an old wives tale.

Shit..... I wake up miserable after the visit to the dentist yesterday. Now I'm finding myself agreeing with TV. I don't like the way this day is trending here. LOL

That's allright. Good ideas stand on their own merit.

turtlevette
06-11-2008, 07:56 PM
I think the point that is overlooked here is that the oil separation or liquidizing of the grease is essential for lubrication, cooling. it's what provides the lubracation film. Just the grease itself does not. The bearing is packed with grease, the rest in the cavity is just additional grease to supply the ebaring with grease that's lost when rotating, sort of like the oil sump in your engine is a buffer.

YES!!! The more grease the better the cooling. And yes, there is some risk in the rear bearing housing that the grease will squeeze past the seals and make a mess. I'm willing to accept that.

Dirtbuster1
06-12-2008, 02:10 AM
Guys,

I have some data that will answer all of your questions. It was put together by SKF & Exxon/Mobil. I will have to look through by backup files since I'm not working anymore. If I can't find the files, I will email one of the people I know from either company to get the info need.

I will even get you bearing installation info if needed. If there is any specific info that is needed I will also be glad to get that also.

big2bird
06-12-2008, 02:20 AM
Oh yeh.:trumpet:

Twin_Turbo
06-12-2008, 04:57 PM
I was looking for that SKF PDF info but it appears it's now 5$ a piece, no way I'm gonna spend 5$ on turtle :D

Dirtbuster1
06-12-2008, 06:30 PM
TT,

Which SKF pdf file were you looking for. I will get one of the SKF guys to get it for me. I couldn't find a copy of the lube files I need, a freind is going to send me a copy of the power point slides. It's over 6 megs and I'm having trouble downloading it.

Twin_Turbo
06-12-2008, 06:42 PM
Nothing in particular, but what may contribute to this discussion is lubrication selection and lubrication management & best practices

Dirtbuster1
06-12-2008, 07:42 PM
TT,

I have a word doc that is to big to attach. Can I email this to you for posting?

Herb

Yellow73SB
06-12-2008, 07:46 PM
I put vaseline on mine and they work fine

Twin_Turbo
06-12-2008, 08:35 PM
Herb, you can use twinturbov8 @ gmail.com (remove spaces)