Is a rubbing disc brake dust cover the first symptom of a bad wheel bearing?

Question

Wife came home the other day and said there was a noise when she turned left in the 2014 Chrsyler T&C Minivan. I drove it around a parking lot and confirmed a scraping/metallic rubbing sound from rear wheel (I thought left, she thought right) when turning fairly tight left turns about 10-15 mph. Didn't sound clicky or robust enough to be the wheel bearing. Sounded to me like the brake dust cover rubbing, since I had one bust loose on a truck one time, and this was really similar.

I took a screwdriver and gently pushed the dust covers back a bit, just through the wheel holes. Test on turns and the noise was gone, so that was definitely it.

However, I'm wondering if this is just the first symptom of a bad wheel bearing. If I understand how the stuff is put together down there, the dust cover is attached to an assembly that's independent of the wheel and rotor, so that the shifting of mass during turns may be angling that wheel enough to cause that rub.

To be clear, I don't get any other typical wheel bearing symptoms -- which in my past experience were all a lot more obvious. But I wonder if I should just get ahead of this one and have it replaced.

Answer 1

Your understanding of how it's connected together makes sense, however, if you are rubbing a brake dust cover (backing plate) it doesn't mean the bearing is going bad. The first thing I'd be looking at is if there is any damage to the dust cover or if there is something stuck between the dust cover and the rotor.

The reason you wouldn't look to the wheel bearing first (and I'm NOT saying it CANNOT BE the wheel bearing, just saying you need to eliminate other things first) is because when a wheel bearing starts going bad it is a very small amount of play which it causes. I'm talking about in the .0001" arena type play. You'll feel a wheel bearing before you'll start seeing a problem with clearances, especially something as broad as a how far the dust shield is off the rotor. You can measure the distance with a ruler, not a micrometer.

Answer 2

None of the failed wheel bearings I have had affected the brakes . They caused a very low rumble that you felt more than heard. My first auto repair; driving home in my '41 Cadillac ( cost $ 95 from a Cadillac dealer- used) ,my father said that sound is a bad wheel bearing ; he was correct.

Answer 3

Put that wheel up on a jack so it can spin freely. Then grab each side of the tire with your hands, and are facing the the tire. With a firm touch, wiggle the wheel to side (as if you were trying to make it 'steer'). If you can feel any looseness or play at all, you need a new bearing. I learned this when I worked in an auto shop while I was in college and have used the technique repeatedly to diagnose.

Answer 4

It's unlikely to be a wheel bearing. If the wheel bearing is so worn that the wheel is cocking enough to rub on the disc brake shield, you'd have started hearing it months ago. What I think is more likely is your shield probably got hit by either a rock or some snow and got bent. You bent it back, problem solved. When wheel bearings go, they start as kind of a low moan and if you let them go long enough it sounds like a helicopter chasing you.

Answer 5

Have you replaced the rear discs recently? I had a problem that drove me crazy for a while with my 2007 T&C. I do all my own work, and buy OEM parts when I can, but not usually dealer parts. I'm no beginner with cars or parts and I know for sure I have ordered the correct rear discs for that car twice and both times they rubbed on the dust shields. Barely, just enough to drive me crazy trying to figure it out. Not enough to rub all the time or even put a noticeable mark on the dust shield. Just enough to piss me off.

At one point I was sure it was the parking brakes rubbing and completely disassembled both sides, cleaned and greased, checked and double checked, only to re-assemble everything and have it rub again.

It would never do it when I had the car up in the air, only on corners while driving. I eventually figured out that the discs were somehow different. Larger, but only by a fraction of an inch. Two different brands, same problem.

I fixed it by using a grinder to take just a small amount off the inside edge of both discs where they were close to the shields. I have not had a problem since.

I am not saying that's your problem, just putting this out here.

Answer 6

After having had to push the cover aside again, and the noise came back, my mechanic took a look and told use the rotors were just very rusty outside the areas where they are constantly scrubbed by the pads. The growing rust barnacles were contacting the cover. New rotors solved the issue.