Ceramic wheel bearings?

[Skunksmash]

In my never ending quest for greater fuel economy, I've run across the wheel bearing issue. When its time to replace my wheel bearings, is there a more efficient one that I could use to reduce rolling resistance? I've heard of race cars using ceramic ones with a full synthetic grease. Anyone hear have any thoughts or opinions on better wheel bearings?

[gchemist]

My 96 Jimmy had stock ceramic bearings. I replaced them with steel rolling bearings and good high temp grease. Bearings lasted ~100,000 miles. I'm on a new set. The bearings are cheap and easy to replace. I would suspect races use ceramic bearings for the high temps they run when braking. Probably one time or short time use for them. Either set is good. I think, steel is more sensative to wear if metal shavings start to gall them. Either way, replace the racer or bearings will wear out faster.

[crashz]

Rolling resistance will likely be negligible between steel and ceramic bearings, but grease viscosity may make a slight improvement. So will correct bearing preload. Synthetic lubes through out, skinny tires inflated to max sidewall pressure, and you'll be on you way.

[INSIDIOUS '86]

Ceramic is nice because it can be made to a much greater precision. And they can take more heat without expanding. But a good pothole will kill them.

I run some redline synthetic grease on mine.
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[kalbert]

I'd think ceramic bearings might wear well and have long life, but fuel economy improvement would be minimal at best. Diminishing returns. Use grease rated for the extreme heat and pressure of wheel bearings and set the preload correctly and you've got the most efficient bearings available. I heard of a guy replacing the grease in the wheel bearings of a solar bicycle thinger with WD-40 and various other extremely light oils. Needless to say it did not work as those could not provide a lubricating barrier between the bearing parts, they weren't intended to be able to.

[willett]

The amount your going to spend on ceramic bearings and synthetic races is going to be a lot more than you will ever save in fuel. If it even makes a difference at all.
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[Skunksmash]

Thanks for all the replies, good info here. Sounds to me like the correct bearing preload is the information I was missing. What methods do you guys use to make sure you've got the right preload when you replace bearings? Talked to a friend and he said that he just spins the tire while its jacked up, and if it spins freely for a long time, its right. But I'd rather have a tool or something that tells you.

[willett]

Tighten nut while spinning tire. Keep spinning nut and wheel until nut becomes tight and wheel turns with some resistance. Back the nut off until there is no resistance (usually 1 or 2 flats)



I'm sure there's a torque procedure out there somewhere, but nobody really does it properly in the real workd

[gchemist]

There is no tool to tell you. It's experience on setting the load. I tighten mine until the wheel does not spin freely. It ensures bearings are snug and sealed. I back off until it spins freely. I mean really free. Then I tighten it up again while spinning it every 1/4 turn. I like to get almost a full revolution before setting the cotter pin. Pull the tire outward. If it moves, bearings are too loose. Tighten a little more.

[Rubble]

This is one of those things that everybody has their own way of doing it.When I took my heavy duty mech cert. about 25 years ago,my instructor in the air brakes/ heavy suspension class told us it's always better to have play than preload.I drove truck for twenty years & did most of my own work,whenever I was doing brakes,wheel seals or anything that required removing the wheels,they were always set up with that in mind.I have always done my pickups the same way & never had an issue.like I said,there are lots of other ways too,this one has always worked for me.