Tag Archives: wheel bearing

Bad Wheel Bearing

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Pitted bearing race

Yesterday, I jumped in bowtie6 and went for a drive when not far from home I heard the classic rumble that comes from a bad wheel bearing.  On the way back home, the rumble developed a slight thumping.

I’m like, wtf? 😯 This is the second bad wheel bearing!  Back in April 2012, I posted an article describing the Rear Wheel Bearing Replacement.

So with my cousin Jim’s help, we pulled both rear axles from the housing and inspected their bearings.  Passenger’s side was normal; but the driver’s side bearing was very rough, as expected.

Jim busted the bearing using the same technique I described in the article from last time and sure enough, this is when we discovered the bearing’s race nicely pitted.

The majority of the race was in decent shape, except for the big round pit shown in the picture above.  The ball bearings were not smooth and showed slight pitting with a very dull finish.  Jim explained this is normal when particles from a bearing start to shear off and make a mush of themselves.

Pitted ball bearings from the bad bearing

This picture above shows three of the worse ball bearings – sorry for the picture quality – and as you can see they are rather dull-looking.  The crack on the race was caused by us when we took the thing apart.

RW207-CCRA rear wheel bearing

And of course, this is crappy Chinese-made stuff.  Jim has gone through 3 rear bearings on his TR4 and this is the second failure on bowtie6.  Unfortunately, it appears these wheel bearings are no longer made in the USA and as expected, this is yet another example of poorly made products from China. Jim explained this is bad quality steel on the race and/or the ball bearings and that once the surface starts to peel, it is only a matter of time before failure.

I ran a few queries on Google today and found versions of this type wheel bearing made in Japan.  From what I have read on some forums, the Japanese versions are of a higher quality.  Needless to say, I’ll be ordering some soon.  However if you know where I could find these bearings made in the USA, please let me know.

Driver’s side rear end

Passenger’s side rear end

Passenger’s side axle with good bearing

Rear Wheel Bearing Replacement

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2400 miles driven and one of the two rear axle wheel bearings has failed on a sub 2500lb car.  Sad shape of affairs this is indeed.

Fist off, the wheel bearing in question has the SKF name all over it; made in of all places, China.  I have a problem with offshoring and a bigger problem when the offshored goods are defective.  QA was definitely not in the picture when this bearing was made.  And no, this is not the first one to fail.  My cousin Jim Thompson’s TR4 had the exact same thing happen on an identical rear axle as used on bowtie6.

So what is all this fuss about?  Let me show you.  After lifting the rear of my TR6 up in the air, we were able to determine the driver’s side axle bearing was at fault.  I took the caliper off, then the rotor and the retainer plate off the rear housing.  A couple of strikes with a deadblow hammer and the axle was out.  This is what it looks like:

The picture above shows the bearing and on top of it the retaining ring.  In order to minimize damage to the axle, the bearing is cut as follows:

And once the outside race “pops” (it is under tension and cutting the outside race eventually makes a muffled “pop”), we get a chance to see inside.  This is where things get very interesting:

In the picture above we have the outside race cut showing the ball bearing retainer.  It is what lies below the ball bearings what is of interest!

Here we start to see the root cause of the problem.  The inside race should be slick, polished and accurately ground.  Look at the photo above: the lower half is indeed properly hardened and finished.  However, see the top half?  It looks very rough indeed.  That is where the racket was coming from.  Another couple of pictures:

And…

Further inspection revealed the outside race was in good shape.  No case-hardening issues there.  However, the inner race was very poorly made – somehow the case-hardening process was not properly applied and the surface of the inside race pitted severely after only 2400 miles.  This cannot be blamed on poor lubrication because these are sealed bearings.

A new bearing has been sourced – unfortunately it is SKF.  I just hope I’m not here in another 2500 miles talking about another bad apple.  Here is a photo of the new bearing being pressed in:

Once I got the axle back in the housing and bolted it all back together we were set to go.  I put about 50 miles this afternoon and all is good.  I just keep my fingers crossed the new bearing lasts a little longer.