thinner grease for wheel bearings a hypothetical

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another forum I frequent is all about fuel economy one of the topics of discussion is wheel bearing grease.

Most of the members drive small underpowered front wheel drive cars from the early 90s. Most of those vehicles have tapered roller bearings in the rear axle.

In their contiuning effort to grasp at straws a few have taken to converting their greased rear bearings to a fluid bath. My thought was to go from a ngli #2 to a lower viscosity, like a #1 or even #0 ( #00 was rejected for being too thin to work with and for all intents one may as well go to oil bath at that point)

Anyone with any thoughts?
 
regardless of taper roller bearings or balls, they still need to have proper loading in order to work satisfactorily.

(*our resident bearing guru can help chime in on this subject*)

Of course, one can play with thinner grease (been there, done that back in my Suzuki days).

My biggest gain in fuel mileage has to do with (a) reduced load (body weight), (b) remove sound-deadening materials in the compartment...also: reduction in wind drag, use skinnier tires, etc. all helps.

Q.
 
Yes, but for these guys they have already covered their cars with coroplast , removed the paxirror and installed a plate, run the narrowest lrr tires at the highest pressures... seats removed etc... the straws are all that are left to grasp for.

I will have to look into the friction thing though.... but why then would an oil bath work?
 
also: try waxing the car repeatedly with synthetic car wax purportedly contains PTFE....it may make the entire car "slicker" and less wind resistance also....

*laughs*

Q.
 
And that's what these guys are doing, but there was a comment about roller bearings and not enough friction. Why would thin grease be bad when gear oil or 5w30 isn't?
 
The idea is one of the dumbest wastes of time I have ever heard of. Some people have strange hobbies.
 
Originally Posted By: DoubleWasp
Roller bearings like to do nasty things to themselves when the little rollers don't have enough friction to keep rotating, if I remember correctly.


1st answer was the best. But I think he was being too tongue-in-cheek and it was not appreciated.

The bearings will eat themselves up if gaps in the fluid barrier appear. Not shred and shed, but rather develop hot spots and loose efficiency in a very big way. This is why you cannot "blow dry" roller bearings w/compressed air w/o wrecking them (check any FSM). I guess they are trading 25k vs. 150k bearing replacement intervals vs. short-term rolling friction games. Which won't be cost-effective in the long-term.
 
Oil lubrication IMO is better than grease any day...provided that you can seal it...hub seals are rotating, whereas oil filled bearing seals are usually stationary.

Comments about bearings skidding are valid, if they are too lightly loaded, or the oil too heavily FMed.

You want about 15cst at operating temperature (3-4" mean diameter at 1,000 RPM), whether that's the oil chosen, or the base oil of the grease chosen.

80W gear oil ?

I wouldn't necessarily go for a 5W30 ILSAC engine oil.
 
Why knock tapered roller bearings...if they had a rear hub assembly they would still have tapered bearings inside,you just couldn't grease them.
 
They'd do better at cutting brake friction, but, then again, I'm sure they have. Back off the drum adjuster then disable it and get those springy things for the front pads.
 
Bald tires help, gotta avoid losing energy in "tread squirm". Driving in the rain reduces it even further.
smile.gif
 
Originally Posted By: HerrStig
Bald tires help, gotta avoid losing energy in "tread squirm". Driving in the rain reduces it even further.
smile.gif



Driving in the rain requires pushing the water on the road out of the way. Then there is the slippage issue.....Plus wipers and lights suck up gas, when in use.

Ridiculous things to worry about, because if you have to drive, those things are not optional.
 
Originally Posted By: 4wheeldog
Originally Posted By: HerrStig
Bald tires help, gotta avoid losing energy in "tread squirm". Driving in the rain reduces it even further.
smile.gif



Driving in the rain requires pushing the water on the road out of the way. Then there is the slippage issue.....Plus wipers and lights suck up gas, when in use.

Ridiculous things to worry about, because if you have to drive, those things are not optional.


Depends where you are. Fairly optional here, very optional in, say, Egypt.
 
Originally Posted By: Shannow
Oil lubrication IMO is better than grease any day...provided that you can seal it...hub seals are rotating, whereas oil filled bearing seals are usually stationary.

Comments about bearings skidding are valid, if they are too lightly loaded, or the oil too heavily FMed.

You want about 15cst at operating temperature (3-4" mean diameter at 1,000 RPM), whether that's the oil chosen, or the base oil of the grease chosen.

80W gear oil ?

I wouldn't necessarily go for a 5W30 ILSAC engine oil.



i agree, and ss already stated, trucks run oil lubed bearings, as do pre-90's Land Rovers and those of us that convert their later model Landies to oil lubed hubs using early model hub seals.

I'm not convinced of the roller skidding argument considering how many taper roller bearings are used in diffs and gear boxes/transmissions. (albeit always with pre-load)

We do it to prevent water ingress (the oil seal is superior to the later model grease seals) and to prevent fretting corrosion of the outer axle splines inside the drive flange.
Diff oil is allowed to flow freely up the axle tubes and bath the fully floating axle bearings.
 
I am sure oil would work fine but the gain in mpg would be un-measurable. BTW, what is the name of this sire....I need a good laugh.
 
You guys are barking up the wrong tree. Grease has little to do with rotating friction in a wheel hub. Nearly all the friction comes from the seals.

In all the thousands of failed warranty bearings that have come through our lab, I don't think we've ever seen a bearing that was damaged from skidding. Skidding is more a phenomenon with bearings that see high angular accelerations.
 
This is only my experience. I have an 18' boat on an EZ Loader single axle trailer. I have pulled it from S. Indiana to Central Florida about 25 times, plus local trips. The original axle was drilled so that when grease was inserted it passed through the bearing and was expelled out the rear, behind the (rear) grease seal. I used to use a small (8 oz?) cartridge grease gun to grease the bearings before leaving Indiana and again before leaving Florida. I alternated between boat wheel bearing grease and Mobil 1 synthetic rear end oil. I would pump oil in when leaving Indiana and then grease in when leaving Florida. I checked the bearing temps with an infrared guy every time I stop for fuel. The bearings ran the coolest when I was using the grease-then-oil-then-grease routine. May / may not have been a good idea, but that is what I experienced. Never disassembled the hubs / bearings until the axle failed. It was not the bearings that failed, but the torsion suspension got tired.
 
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