Wheel Bearing

My 2000 Ford Ranger’s left front tire developed uneven wear. It was cupping and wearing more on the inside. An alignment showed not much off spec.

Also, my ABS kicks on when braking at a slow speed while turning to the left slightly. An auto technician determined the left front wheel to be eratic (tends to slow down quicker and speed up slower than the other wheels).

Could both these be realted to a worn wheel bearing on the left front?

If so how do you check for worn wheel bearings?

What is the going rate to replace wheel bearings?

And do you need to have the vehicle realigned after the repair?

Thanks so much,


Could be a wheel bearing, could be something else too. You can push and pull on the top of your tire and any looseness would be indicative or a loose wheel bearing, also it may sound like you have snow tires on. You may need an alignment after repair. On usual wheel bearing jobs it is not necessary but given the wear on your tire indicating a bad alignment it would be good to have it checked. Cupping is usually a shock thing but who knows. A wheel bearing replacement should not be too expensive but it would be good to get it done before you damage your axle.

Why did not the same tech that gave your your “eratic” diagnosis also check your wheel bearing?


I appreciate your reply.

These are not snow tires. All the tires have some slight cupping. So lets put the cupping aside and concentrate on one tire, the left front.

The left front had more wear (not just cupping) on the inner most edge (from the inner edge to about one inch in). I’m talking wearing down.

My main question is still can both (irregular tire wear described above and my ABS activating as I originally described) be due to a bad wheel bearing?

It would seem that a bad wheel bearing would cause the wheel to slow down faster than the other three. And stearing left would make it slow down even more. Does that make sense?


If I can get one of you pros to confirm a bad wheel bearing is the likely culprit, then I may go back to the “same tech” and asked him if he checked the wheel bearing.

Understand I paid for an alignment when I took the vehicle in. If the wheel bearing replacement requires a new alignment then I will go back to the same place (they will do the alignment for free).

Sorry I did not make it clear but a bad wheel bearing can make a sound similar to the sound if you had snow tires on, a low rumbled growl so to speak. Your tire wear is an indicator of a problem, could be the bearing, could be the ball joint, could be a tie rod, could be a bad bushing, And if your tire is showing that bad of a problem you need something fixed, SOON!

Un-intended ABS activation and excessive inside edge tire wear are the symptons, I do not link the problems and I opine that the tire wear is an alignment issue and the ABS sympton is caused by a control unit issue. I am skeptical about your apprasial that the ABS is activating on one wheel without input from you. Bad bearing is way down the list as being the cause of both these symptons even if the ABS sympton is real.

What got you going down the path of bad bearing in the first place? Not that humorous “eratic” diagnosis was it?

When a inner or outer front wheel bearing fails it can be catastrophic (and there is no dobut what has happened) or just fail in a sense that it makes some noise when driving straight and more so when a load from the side is put on it (as in turning). Your talking about a bearing failing and causing slower turning speed (I guess that is true when the wheel is just flopping around) when spun by hand. At times you can hear and feel roughness and a noise but judging a bearing bad by comparing how long one wheel spins compared to another is not a full test.

Unless the bearing was so bad that the wheel had visible movement in it it will not affect the ABS, noisy bearings do not affect the ABS.

If you bearing was so bad it was affecting the alignment a quick check by grasping the wheel and giving it a shake would detect this.

To check a wheel bearing: Jack the wheel off the ground. Jiggle the tire back and forth to see if there is any play in the bearing. A bad bearing will result in play between the hub and spindle. Then spin the tire with your hand. It should rotate smoothly and silently…Your problems do not sound like a wheel bearing…

Worn inner edge of the left front could point to a loose wheel bearing or too much negative camber. The latter can be caused by a worn suspension part or a bent one.

So what are the specs and just how much are you talking about when referring to “not much off spec”? It doesn’t take much to wear a tire.

I wonder if perhaps you don’t have some other cause of brake pulsation like a warped disk rotor that you are confusing with the ABS kicking in. Can a bad wheel bearing cause brake pulsation? I’d think so, but that didn’t happen with any of the several wheel bearings I’ve had fail over the years. Whatever the problem, if it is anything other than an alignment issue, it could well be something that you want to deal with before the left front wheel decides to part company with the car.

Cupping is usually a sign of bad shocks. Uneven wear is usually a problem with alignment. Also, worn suspension parts, like bushings and ball joints can be causing this. And a bad tire that is breaking down internally.

Bearing failure first starts out with a rumble or growl. It gets worse until total bearing failure and loss of wheel. The steps mentioned many times above are accurate for testing wheel bearings.

I’m questioning the logic of the ‘speed up and slow down’ advice you received. This sounds like bad BS to me. The ABS system is designed to already recognize slightly different wheel speeds when turning. The ABS system should not kick in until it senses a wheel lock-up. I’d check the wheel sensor and encoder ring for damage.

To all,

I appreciate all of your responses. I’m going to stop by the auto shop tomorrow and ask about the wheel bearing. If I do not get a firm response from them I will jack it up and check it myself.

I was not completely satisfied with the shop I took it to. They could not give me a printout of the alignment because their printer was not working. I questioned them a couple of times about it and they said I could bring it back and put it on the alignment rack to get a printout. Hence the reason I can not give ok4450 the alignment results. The tech could only tell me the one wheel (I assume the left front) was not far off from spec. Some of the linkage on the front end was replaced prior to my recent purchase of the truck. It’s possible that they did not do a proper alignment at that time.

They said everything was tight on the front suspension and felt the issue with the ABS engaging while braking at a low speed and turning the steering wheel to the left might be due to a bad wheel sensor ($300) or the ABS module ($1,000). They could not be sure because their wheel sensor diagnostic equipment only digs down so far. Their equipment determined that the left front wheel sensor transmitted a reading that the wheel was not moving (slower) at the same speed as the other three. The guy in charge suggested taking it to a Ford dealer. Supposedly they have more sophisticated equipment that can dig down deeper.

After I got home I started thinking about, “alignment not far off spec”, inner most edge of tire is wearing down, and my left front wheel sensor is sending a reading that the wheel is moving slow. So I’m thinking maybe there is something causing the wheel to move slower. Like a wheel bearing going bad. That’s also causing my tire to wear when the alignment is not far off spec.

However, I’m somewhat skeptical that the wheel bearing is going bad. I would label myself as a very sensitive driver and I am certain I would notice the noise.

So you pumped the Forum to guess while you witheld info from a shop, do I have it right? I guess all is fair within the web.


What “info” are you referring to that I withheld from the shop? I’m not here to pump a forum. I’m here to get answeres.

So I’m thinking maybe there is something causing the wheel to move slower. Like a wheel bearing going bad.

I’m wrong sometimes, but I think a tire that was actually turning slower than the others (on average) would be wearing very rapidly over the full contact area, overheating, and probably smoking after being driven any distance. … On pavement anyway … If you drive mostly on unpaved roads, it’d be different.

The info that you were already told you might have a bad wheel sensor,the info that you were already told you might have a bad control module and the apprasial that you yourself don’t believe you have a bad bearing.

You also witheld the depth of your contact with the shop that looked at your car. You state the shop reached their limit of ability and suggested you take it to the Dealer.

Any shop that went this far into searching for the cause of your problem would also have checked your bearings.

Am I misinterpeting the order of events? When you say “I am taking the car to the shop tomorrow” and then in your next paragraph are you talking about a previous visit or a new visit when you state you are not happy with your visit to the shop?

I interpeted from your post that the info about the possibility of a sensor being bad etc. came to you at your first visit to a shop and you did not include this info in your original post.


I apologize. I did skip around a little. It’s difficult explaining when there are many issue taking place. Also, every word counts (i.e. 'not completely statisfied" is not the same as not happy, “skeptical” is not the same as don’t believe).

Anyhow, I jacked it up myself and tugged the wheel up and down spun it and did not notice any play or noise.

I had read one time that a slightly loose wheel bearing that is allowing the segment ring to contact the wheel sensor could cause the ABS to engage unexpectedly while braking at slow speeds.

For now I will have to wait and see how the tire rotated to the left front wears.

I will watch the

I have much respect for a non-mechanic to come out and so clearly state why they are suspicious of a situation being a certain way. You cleary stated why you feel the bearing could be the problem. I don’t really like the theory that the ring and sensor could come into contact with the only result being unintended ABS activation, I would think that would leave a mark. When I read your post I thought “why would this person think the problem was with the bearing and why didn’t the inspecting mechanic say something if the bearing was bad”?

Many people who post, and I try very hard to pick out which ones, leave out, or state they were told things or things happened is such and such a way. But I and most other regulars here know how things procede in the garage and how mechanics are trained to do the work,so I pick-up on these irregularities quickly.