Tire wear Alignment Control Arm

[svx_commuter]

I am having trouble with the front right tire wear. It is getting that washboard wear on the inside the tire. This has been going on for awhile now. I have taken it to different shops and no one has found the problem. The alignment has been checked and it is within spec.

They all say the lower control arm bushings are fine. Pushing and pulling on the arm with bars to get the bushings to move does not reveal any loose bushings or bushing defects. All the sub-frame bolts are tight. The shocks have been replaced and the ball joints and upper strut mount are good.

It seems as the tire wear progresses that a noise and vibration starts to emanate from the right front during braking.

So I am thinking that the lower control arm is worn out and it moves out of place when braking heavily and the alignment goes to poop when the arm moves. The forces on the control arm bushings way higher during braking than poking around with a bar and looking for loose parts.

I am also wondering if it’s a defective tire and the wear is just coming from the defect. I could put the rear tire up front and see if it does the same thing.

The front bearings have been checked and they are okay.

Any thought on this would be most appreciated.

[Beav]

Are the scallops evenly spaced or irregular?

[svx_commuter]

The scallops have been evenly spaced on this set of tires and the last ones that wore out. Evenly spaced all the way around. The last set of tires had scallops on both tires, left and right, and then after rotating the tires I ended up with four that are scalloped. The right front always seems to be the worse.

The last time I sanded down the tires, this past weekend, the scallops were a little deeper on one side than the other. I did NOT get them balanced after sanding them down the past two times. So I am thinking it may be from that.

I am also thinking about the front right wheel bearing. I had the axle out this past weekend and the rotor off so I could feel the bearing. It rotated very freely and sounded dry. The bearing had NO clicks or rough spots in it, no loosness and excessive pre-load. I think it may have been in this dry condition for about 50k miles. The grease blew out when I was at a time trial 2 years ago. So I tried to force some grease into it through the seal. This greatly reduced the free spinning. However, I don't know if this a factor or not.

The other I have is slotted rotors so I am think about changing them to non-slotted to see if the vibration goes away. To find out if the vibration is from the slots.

[mbtoloczko]

If the bearing is dry, I'd guess you'd want to replace it for at least that reason anyhow? I'm surprised that a bearing would last more than a few hours if it were dry.

[Beav]

Evenly spaced scallops are from an out-of-balance condition. Loose parts cause irregular scallops as the motion is random. Balance problems are consistent in their location and as such leave a consistent pattern. Wheel bearing wear would be inconsistent by nature of the way a bearing moves. Rotor slots would only come into play during braking and if they were causing a wear pattern on your tires I'd be more concerned with what was grossly loose enough to allow them to create the wear.

[svx_commuter]

Beav, thanks for the reply I really do appreciate your experience in these matters. I think there might be a misunderstanding about the scallops. The spacing between the scallops is about 3 inches all around the tire on the inside, more of a washboard effect. I am having a difficult time understanding the effect balance would have to create this wear pattern. I think out of balance would make one side of the tire wear more than the other, as in 180 degrees apart, one side heavier than the other.

I have been told that the scalloping on the inside of the tire comes from too much toe out. I have tried messing with the toe but it doesn’t help.

Harry, newsvx has had scallop wear on his tires when the camber was set to 1.5 degrees. Says it handled great but got too noisy. So he went back to .5 degrees.

I am thinking that the bearing is the problem. Do you think this makes sense? The bearing when it is cool has all the proper clearance and checks out okay. Then when I drive the bearing gets too hot because it doesn’t have enough grease in it. Now it gets hot and the clearance opens up. So the wheel can wobble around on the loose bearing. This allows the wheel camber to change and makes the tire wear.

[Beav]

Hmmm... a double post. I guess the powers that be deem it necessary to protect us from deleting our own posts. I love people that protect me from myself, it makes me feel all warm and fuzzy.

[Beav]

Toe and camber both cause smooth edge wear. Camber will create a feather edge on each rib. Think of a paper cup laying on its side. As it rolls one side is turning faster than the other. Toe is just dragging the rubber sideways, like an eraser. Balance is hopping up and down in the same spot(s). Loose parts and shocks are hopping and wobbling randomly.

180 degree separation would account for first order imbalance, what about second and third order imbalance?

No amount of toe will create scallops, unless the wheel doesn't spin. Then you'll have one HUGE scallop. (p.s. the leading edge is the one that will show wear.)

[svx_commuter]

Yeah I agree with you. The tire wear should be smooth. That is what I am used to seeing. I know a few people that have had this type of tire wear in a short time.

I think I have that featheredge on each rib also in addition to the scallops. I am not sure how to describe it. I see this pattern around the tire; each section of the tire between the grooves becomes wedge shaped. Is this what you are you talking about?

[Beav]

Yup. 56789

I'm sure someone thinks there's a good reason for this.

[svx_commuter]

I have been geeting my wheels balanced on a Hoffman machine, wheel alignment on a Hoffman machine so the tire effect isn't there and I have been having these problems with scallopeeny tires for three years.

[SVXRide]

How about posting a picture or two of the tire?
(I'm with Beav as to what would/should cause the wear that has been described - fits with what I was taught way back in autoshop... )
-Bill

[svx_commuter]

Yes I would like to post some pictures. Maybe this weekend. I got really crappy camera.

So what is the tire wear pattern for a bad wheel bearing? or a loose wheel bearing?

[Beav]

Originally Posted by svx_commuter

I have been geeting my wheels balanced on a Hoffman machine, wheel alignment on a Hoffman machine so the tire effect isn't there and I have been having these problems with scallopeeny tires for three years.

Maybe you need to geet your wheels balanced and aligned somewhere else?

DOC!!! It hurts when I do this!

heheheh...I couldn't resist

[oab_au]

It is caused by out of ballance. Are the wheels dynamically ballanced?
Have they placed the weights on the edge of the rim, or have they stuck them on the back of the rim, so they can't be seen?

The wheel may be in static ballance, but out of ballance when spinning (dynamic). I have seen a wheel spun on a dynamic ballancer to find the spot, but instead of fitting the weight on the edge of the rim, where it should be, they stick them all on the back, in the center of the rim, so they can't be seen.

Harvey.