Bright metal shavings on wheel sensor

My abs light came on and my code reader read RR sensor no signal. Replaced the sensor and inspected the abs ring by looking in the sensor hole. Looked shiny, clean and intact. Sprayed carb cleaner in and blew it out. The abs light is still on after clearing it a couple of times. I’ll dig in to the wiring further when I have time but I have a question meanwhile.

It’s a front wheel drive car with the typical sealed bearings in the rear. The old magnetic abs sensor I removed was lightly coated with shiny metal bits. Could these metal shavings be an indication of a bearing starting to go bad. No noise or typical rumbling that I can detect at this time. Thanks.

131,000 mile on car.

Your wheel bearings are wearing out. That means the whole hub has to be changed. The wheel bearings may feel good to right now, but they have enough wear on them to cause the reluctor to hit the ABS sensor.

I’m surprised that you haven’t hear the “roar of the wheel bearings” yet. You soon will.


Thanks Keith and I see Mustangman agrees.

………Time to order a new hub.

My sensor wire was 8” long? Plugged into 2nd wire that was 18” long? The 2nd plug was under fender liner. Maybe you have a frayed wire somewhere. My code for wheel sensor was not fixed with new wheel bearing. Maybe it was my downstream wire?

The Kia abs connection is inside, high and dry in the passenger compartment behind some panels. All the wiring did appear to be in perfect condition. I will look again.
It’s the shiny metal bits on the sensor that got me thinking, where did it come from?
No play and, unless my old ears are really shot, ……no rumble or roar. Thanks

We usually think of wheel bearings making noise, but that is not always the case, especially on the front wheels when the front wheels are driven.

Other noises can mask the wheel bearing noises. I never heard any noises from the front wheel bearing on my 4wd truck. First the ABS light came on and a couple days later the wheel wobbled so bad it almost came off. The wobble happened suddenly.

I had another car that had a bad wheel bearing on the rear, factory defect but the OEM tires were so noisy that I didn’t notice until I bought new tires. That wheel bearing was so distorted that I couldn’t get the hub out of the knuckle. The wheel bearing on the other side slid right out like it was supposed to.

The metal shavings were the big clue for me.

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Follow up….
I went out for a ride today and measured the temperature at each wheel bearing. The suspect bearing was about 10* higher than the other three. Between the metal shavings and the higher temperature it looks like the bearing is on the way out. My old sensor might have failed to signal because of the metal shavings but I did determine it wasn’t because of bearing wear and air gap widening “yet” , but weak, almost 74 y.o., eyes.
When I put the new sensor in I failed to see the rust build up in the sensor hole and consequently the new sensor still had approximately 1/16” - 1/8” more to go in. I deburred the hole and now the new sensor sits flush and the abs stays off.

At least now I can wait until this arctic blast passes over these W.V. hills before I go outside to install the new bearing. Thanks

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