If a wheel hits a pothole or curb enough, the incident can cause a small imperfection in the surface that grows. In this video, the experts from Timken show how one impact can cause fatigue in the steel of a bearing.
What should a technician look at when they pull a wheel bearing or hub unit out of the box or off the car? In this video, Andrew Markel from ShopOwner and Brett Blauner from Timken discuss that with regard to the performance of a bearing, it’s what you can’t see that’s critical. The quality of the material really leads to the performance of the bearing.
In other words, a fancy painted or E-coated finish on a bearing does not mean that it’s a high-quality bearing and therefore you may or may not get the performance that you’re expecting.
What can’t the technician see?
One of the things that contributes to the performance and durability of the bearing is the quality of the steel. The cleanliness and quality of the steel leads to the bearing’s long-lasting fatigue life. In fact, oftentimes when you look at a value line bearing, the quality of the steel is such that you’re not going to get the fatigue life and that bearings will spall.
Inclusions in the steel are an area where the spalling will initiate and that tends to be below the surface of the steel. For the technician, what is spalling and how should they look at it or inspect for it on a field wheel bearing?
Spalling, Blauner explains, is the natural death of a bearing. Just as with a coat hanger, you have a rolling element creating a cyclical load that eventually leads to fatigue, and material will actually flake out of the raceway. That’s called spalling.
What are some of the signs and symptoms of this spalling effect behind the wheel?
Eventually what you’ll see is additional material flake out and it will lead to a humming noise or a whirling noise in the wheel end.
Eventually this damage will lead to endplay, and you’ll get some vibration eventually, and potentially the bearing could lock up.
Some hub units have an ABS sensor integrated into it. Unfortunately, a spalled or failed bearing may not even be picked up by ABS. Typically it will be noticed because of noise and vibration in the front end.
What should a shop owner, service advisor or technician pay attention to before they install a wheel hub or wheel bearing set?
Blauner explains reiterates that the majority of the things that lead to the performance of the bearing will not be seen. Whether it’s surface finished, geometry, the material, the cleanliness in the material or the heat treat, the best course of action is to go with a trusted brand.
If you’ve got a choice to sell a value line and a trusted brand, why would you put at risk a long-term repeat customer and save $30 or $40? There’s a good chance that’s going to lead to a comeback.
In other words, probably the most expensive thing in the whole equation is a shop’s reputation.
This video is sponsored by The Group Training Academy.
