by Pat Goss
Daily driving can sure take a toll on our vehicles. But not to worry, Pat Goss is here with the info we need on a sensitive topic
PAT GOSS: Most drivers wouldn’t know a hub bearing from a wind shield wiper, but hub bearings are an integral part of all vehicles and they’re a lot more complicated than they used to be. And we have Tom Taylor our internet parts guru to give us some tips. Tom welcome back to Goss’ garage.
TOM TAYLOR: Thanks for having me Pat.
PAT GOSS: Ok, what do you have for us here?
TOM TAYLOR: Like you said, the driver may not know they have a problem with their wheel hub bearing until a light comes on in their dash their ABS warning light or their traction control light. There’s electronics now in these hub bearings, it’s not just a mechanical part. I’ve got several different examples of how they look and the electronic part is the wheel speed sensor that the ABS system uses the traction control system uses.
This is sort of the original design here where you have a ring that’s spinning and a sensor that’s moderating the gaps in there to measure wheel speed and then we have a version here where the wheel speed sensor is incorporated into the hub another version of that here. And then this one there’s a separate system like this and the ring is actually incorporated into this gasket like material and the problems arise over time you have road debris and bits of brake and junk builds up on this slightly magnetic ring and it screws up the sensor signal and that light goes on in the dash. Over time you get a mess like this where you have all this grit and grime and if there’s too much grease that will attract the crud.
Another problem can be if rust builds up between the brake rotor and the hub surface. Rust actually takes up more space than the actual materials when water freezes and turns into ice it expands that can actually force the rotor out of alignment with the hub and the driver will start complaining about the brake pedal pulsing and think the brake rotors are warped, actually it’s just that rust. The good news is sometimes you can repair these problems just by taking off the hub cleaning off the surface, not with a giant magnet that’ll wreck the sensor, but with compressed air or soap and water and cleaning off the rust built up on the hub so if it’s making the rotor go out of whack.
PAT GOSS: Yeah, that works well. We in the shop we coat the hub surface behind the rotor and the surface of the rotor with anti-seize compound. And one of the things we see a lot of are wheels like this one down here where there’s never been any kind of protection, no lubricant behind the wheel and it just eats the alloy of the wheel into oblivion.
TOM TAYLOR: Yeah, dissimilar metals, aluminum against steel that’s instant corrosion.
PAT GOSS: Ok, well Tom I want to thank you very much. And if you have a question or comment drop me a line right here at MotorWeek.