Question regarding irregular tire wear on the xB

[nickreich]

My girlfriend's Scion xB (06) just recently had new tires put on all the way around. After about 13,000 miles she noticed a bad wobble coming from the left rear tire. I drove it and did notice the same slight wobble.

I do have an intermediate knowledge of auto repair. My first instinct was she somehow threw her wheel off balance. Upon inspection I noticed the wheel weights for balance were still there.

Since the tires were still under warranty I took her car to Big 10 Tire, but it was closed down, so I went to another one. It turned out the tire had developed a flat spot.

To explain further, if you took the tire off the car and placed in on the ground vertical and stood over it with the tire between you legs and looked straight down from the top the flat spot was long and narrow and went diagonal across the tire. Kind of like a "|\|" and there was a smaller flat spot right below it going in the same direction.

Big ten told me it was from a lack of rotation. But I didn't believe them. I have almost 18000 miles on my tires and they haven't been rotated and they are wearing just fine on my toyota corolla. (The front might have a couple tenths of a inch less tread)

His excuse for the abnormal tire wear was because the xB doesn't have a lot of weight in the back, the tires bounce on and off full load and that can develop a flat spot.



I immediately called bullshit. I explained the only two ways I've EVER heard of a tire getting a flatspot is from a car sitting for a REALLY long time without moving OR slamming on your breaks at great speed and skidding for a long distance. My buddy did that once in his fox body mustang, flatspotted all four tires.

They told us they wouldn't be replacing the tire and that they would happily sell us a nice one. I took our business elsewhere.

Today her father came down here to florida and took care of replacing the rear tires and rotating them. We went to Tire Kingdom when I asked about this irregular wear some young kid told me it was either a bad alignment or a sign that her rear struts may be starting to go.

I don't want to have her, her father, or myself have to deal with tires for atleast another 40k miles.


Thanks for reading my story, if you have had this occur to you or may have some further insight I ask that you please respond. Thanks in advance.

Here is some information that may be of use when considering if it may be the struts.

'06 Scion xB
46k Miles

Thanks again

[HATEnFATE]

You may have an alignment issue or maybe the rear shocks are starting to fade and might need to be replaced. It's got nothing to do with weight. If that was the case, ALL xB's would be having this issue and your first set of tires would have had the same issue.

Check out your shocks and also make sure the wheel bearing is ok. No movement of anykind on the rear tire. Take it to a reputable place that you trust and ask them to take a look for you if your not comfortable making the judgment call on worn componants. If your at almost 50k and haven't had a alignment done....get that done either way.

[nickreich]

Thanks for the advice. I'll let you know how it goes and report back.