Wheel Bearing Noise

Took the Lola out for a spin and heard a very bad sound when moving. I determined it was coming from the right front wheel. A dry, metallic clicking/squeaking grinding sound that has no place in a Lola. Took apart, inspected the bearing (P/N 513019) and could find nothing unusual; rotated with no hard spots or other bad things. (The bearing is sealed so all I could do was rotate it) Put back on car and same issue. Hmmm...
Swapped the front bearings left to right and now the noise is on the left side. OK, it's the bearing unit. Ordered a new one (from Amazon, and free shipping, there in two days!) Installed new bearing and all is well.
Then I took the old unit apart by cutting off the cap. removing the lock nut and pressing out the bearings. I expected metal shards but found nothing unusual, Plenty of grease, no flat spots etc.

Any ideas what could cause a horrible sound but yet appear to be a good bearing?
 
Micro pitting. Also can have arc pitting if someone has welded on it with a tig and didn't have it grounded properly or close to where they were welding. Could be also if someone hammered on the bearing to install it .
 

Mike

Lifetime Supporter
I always thought bearings and races are married. Switching bearings and not switching races seems would not be advisable?
 
Its an RCR, don't they use GM wheel brg assy's?, Two thrust type ball races side by side? if so it only takes one small flake of metal to make them run rough.
 

Dave Bilyk

Dave Bilyk
Supporter
The noise you heard does sound more like debris but Impact due to accident or kerbing or harsh assembly technique? Look with a magnifying glass for indentations on the raceways. I had an instance where my road car was hit while parked. After body repair I heard a droning sound which turned out to be indentations made by balls in the raceway due to the impact, I couldn't see anything by eye, but saw the indentations clearly through a lens.
Dave
 
Thanks for the thoughts!
I did an autopsy on the bearing assembly. It is sealed with no means of adjustment. There are two races, the inner balls take thrust and radial forces; the outer takes just radial. I checked the inner races and balls carefully with a loupe, no indication of pitting or anything unusual. I pressed the outer ball bearing off. It too rotates freely with nothing unusual.

Based on the noise it was making I expected shrapnel to pour out!

However, I did notice that it appears the outer bearing spun on the spindle. The spindle should have a nice machined or ground diameter with a 8-16 rms finish but instead is galled. It was a gorilla to press off where it should have been an easy press fit. Hmmmmm....

I never hit a curb (kerb?) or any other activity that would damage the bearing. Could it have been assembled incorrectly causing early failure? Nothing else makes sense.
 
Mic the balls at many places on the balls there has been in the past bad batches of balls
And yes it could have been damaged during manufacturing or assembly.
 
Part number 513019, is a C4 Corvette Wheel Hub and Bearing Assembly, which is commonly used on RCR's. However, if it's the one that came from RCR, they are likely the "budget" bearing assembly you can buy for $50-60, and their longevity is questionable. They just get you on the road....

To avoid any bearing issues early on, I replaced all mine with the Timken assemblies (Front/Rear) which usually run over $160 or so. No issues yet at 5000 miles and some track use. Try Rock Auto or Summit for best prices on Timken.

There are higher performance hub assemblies available from the online Corvette shops for the serious racers, but last I checked they were over $600 each. For the amount of driving we do and the lighter weight of our cars, just stick with a good quality assembly. I chose Timken.
 

Dave Bilyk

Dave Bilyk
Supporter
Distortion of inner race could be the issue based on your description:
However, I did notice that it appears the outer bearing spun on the spindle. The spindle should have a nice machined or ground diameter with a 8-16 rms finish but instead is galled. It was a gorilla to press off where it should have been an easy press fit. Hmmmmm....

A couple of possible explanations based on a small spindle diameter or large brg bore;
Resulting in a slack bearing inner race, which could explain the noise if the bearing did not seize totally and continued to rotate.
or
The bearing inner race rotated until it galled, distorting the inner race and causing noise especially if it was sufficient to pinch the balls (ouch) :stunned: .

Dave
 
If the race rotated to the point of galling on the spindle then that likely caused some heat....perhaps enough heat to distort the race so the bearing doesn't run true anymore.

Definitely use high quality bearings....SKF, Timken, etc. If you've seen how bearings (races, balls, cages, etc.) are made then you know there's high quality manufacturing, and also marginal/not so high quality. The difference is measured in microns and neither this nor the metallurgy is readily apparent to the naked eye. The interface between bearing and race is really, really small. Companies like SKF and Timken have proven technologies and manufacturing processes, and extensive QC procedures.

There's a lot of poor quality cheaply manufactured bearings out there. Spend a bit extra and get a quality product.
 
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