RRocket

When the wheel bearing was replaced on my LS430 after the raccoon mishap, I asked for the old one. I thought I'd take it apart, buy 2 new bearings, and put it back together and use it for a spare should I ever need one.

Well, I was quite shocked when I got the hub apart. Instead of finding a couple of bearing units, it's was different. The ***** themselves sit in Delrin retainers rings. And the "race" is machined right into the hub. And the retainers sit inside the hub packed with grease. This was very surprising to me. But at the same time, I see room for opportunity. Like replacing the ball bearings with ceramic ones.

I don't see any reason why it can't be done, since ceramic bearings are even harder than steel bearings. Cost would be about $10 a ball I think..and there's 22 *****. Even at that price, it's significantly cheaper than a new one. And should far exceed the life of regular bearings.

Any comments?

Tom57

Placing new ceramic ball bearings into used (worn) metal parts sounds like a formula for disaster. It sounds like you have some engineering knowledge, so you know that even the smallest imperfection in the mating of ball, race and bearing could result in premature wear, or worse. Also, there is significant heat generated in the ball bearings from friction, and the ceramic could be incompatible. Interesting idea, but the days of changing out just the bearings and race on older cars doesn't appeal to me for a sealed wheel bearing on a LS. I drive LS for the reliability, and don't ever want any failure, especially on long-distance travels.

Edit: $220 for 22 ceramic ***** doesn't make this a viable cost-effective or risk-reward choice.

RRocket

Ceramic is significantly lighter, so it has less outward pressure on the race. They generate much less friction, so heat isn't a factor as there's no heat build up. And ceramic is impervious to oxidation, and chemicals...and they don't even need grease...just a bit of specialized oil.

You do raise a point about a worn race. The race doesn't look worn (looked under 60 power magnification). I'm not even sure the bearing was worn...the original grease was a bit contaminated by water however. The ***** measure .4997...but that .0003 could merely be the error within our measuring tool.

Thanks for you thoughts!

Tom57

What are your thoughts regarding the cost effectiveness of your proposal (new wheel bearing vs. ceramic ball bearing rebuilt), as well as the risk of trying this idea but it fails? (See edit in my original post.)

RRocket

Yes, yes! There's always that, isn't there? Considering the price of a new OEM Lexus wheel hub...depending on where you get it is $300+ USD. A hub in Canada is $700..(I'm in Canada BTW). But you can get off brand hubs for $75 or so.

So yea...there's definitely that risk. I don't think there will be an "failure" in the true sense of the word. The failure will just be a loud hub.

But yes...risk/reward definitely something to think about.

BradTank

I remember I went on a tour of the Porsche USA proving facility and on some new models they are making the brake rotors out of carbon ceramic and one of the engineers was giving us an in depth over view.

The carbon ceramic rotors supposedly last (nearly) forever (unless they crack) and are lighter.
Only problem? They cost like $10,000 a side to replace.

I'm sure eventually this technology will trickle down, but for most automakers, a part that will last 100k miles and is cost efficient is usually all they care about.

I know I would MUCH rather have the "standard" rotor on the Porsche than this upgraded model if the replacement cost was that high.

Tom57

Pretty ingenious idea, although a home-made ceramic ball bearing wheel hub would be comparable to an "off brand" hub but cost so much more. You also wouldn't know the longevity until you put it into use. As an alternative, I'd use a Toyo or Moog wheel hub to save a few dollars but not compromise on quality.

RRocket

Tom,

The hub isn't home made. That's a Lexus hub with Lexus bearings. The only thing I'd be doing is substituting ceramic ***** for the metals ones. Nothing else is changed.

airchomper

I like your moxy, OP.

You've got your thinking cap on - rebuilding this with ceramic ***** could be cheaper than getting a new hub. And you'd probably learn a thing or two.

The only concern I'd have is whether or not the outer ring is round and whether it has an appropriate finish for ceramic bearings? Timkin advertising 'super finished steel rings' on their hybrid bearings. A microscope could show you the grain of the metal. If it were my money, I'd get Koyo or SKF ceramic *****. Koyo is the OEM for the hubs and I think Japanese precision machining is #1 and I don't have a ton of experience with SKF bearings, but their seals are amazing. I don't think I've ever seen a motorcycle with a blown SKF fork seal.

Hybrid ceramic bearings are becoming popular in motorcycle racing. I don't have hard data, but it seems like steel bearings are more shock resistant. I don't know how much shock resistance you need to survive a pothole in an LS, though? Do you run the 16 inch tires? That would certainly help cushion the bearing. That'd be my only worry (assuming you find out whether your current finish works and if your hub is round).

Lastly, it could be a bit weird for the differential if you had a ceramic bearing on one rear wheel but not the other? The ceramic bearing would be much lower friction than the other bearing. These are open diffs so it might be fine but at the margin your differential could wear in a weird way.

Go for it dude! It could work really well.

RRocket

This is the front wheel hub, not the rear.

And in this application, there is no "super finished steel rings" because the hub itself serves as the ring; and the hub is just a machined steel casting.

airchomper

Don't let me stop you!

My only point is that the manufacturers of hybrid ceramic steel bearings seem to take care to make sure the steel is in great shape. If you think your hub is good enough, what are you waiting for?

If it were my money, I'd try to find a way to polish the hub. Ceramic ***** aren't as shock tolerant as steel ***** and the steel hub might be work hardened so any imperfections in the hub could be catastrophic to the bearing.

RRocket

That's actually untrue. Thin ceramic has poor shock resistance. If you made one thin like spaghetti, it would snap. But in solid ball form, ceramic (it's actually silicon nitride) is incredibly strong...and stronger than steel *****. You can hit them laying on a piece of steel with a hammer and the ceramic ball will leave a dent in the steel. Whereas some steel ***** will ever so slightly flatten after 2 tons of pressure, cermaic ***** can be pushed to 20 tons. Of course, this is Grade 5. I'm sure cheapo stuff might shatter. But when we're talking quality ceramic...the shock resistance is superior.

What type of shock are you thinking about within the extremely tight confines of a wheel hub?

airchomper

It'd be kosher to cite that argument.

And if you have your answer, why are you bothering posting here? Go build your hybrid bearing.

Tom57

I know the hub itself is OEM. I was referring to the entire hub assembly with your ceramic ***** as being made in the garage, not production, but a one-off, experimental home made wheel hub. Nothing pejorative.

After you spend $220 for the ceramic *****, assemble and put this custom wheel hub into use, come back and let us know how it's working as you log miles.