Wheel Alignment - Tires Scalloped?

[JI737]

So I went this week to get my tires rotated, as normal, and the guy tells me he won't do it, because they are wearing irregularly. He used a strange southern-accented term that I didn't quite understand, but said the front tires were shaped like a seashell (maybe he said scalloped? must have been). So, assuming the front tires are mildly scalloped (I honestly can't see much from my untrained eye looking at it, and at the last rotation there was no mention of it, but the place I got them rotated doesn't do anything but rotation, so I trust the diagnosis), what would you do? Go ahead and get the tires aligned, or is it maybe a shock problem? I'm always wary to pay to fix something that isn't actually the cause...Thanks

[jake75]

A couple years or so ago several here got their OEM Conti's replaced at about 20,000 miles for that reason - there was a TSB on it. The dealer fought it a bit and made me prove that I had rotated them about every 6,000 miles. They did charge me for mounting and balancing, and also I followed their advice and got an alignment which I may or may not have needed. They never tell you if the car was out of alignment.

[joatmon]

my car does that to the tires on the right side. If both the front ones are getting scalloped, or perhaps "cupped" then I guess it could be an alignment problem. I'm surprised they wouldn't rotate the tires for you, part of the purpose of rotation is to spread that kind of stuff across all the tires, helping extend the life. That's why i do it anyway. I'd rather replace the tires in a set than just a pair at a time. What kind of tires do you have on the car, and how many miles do they have on them?

[Kamikaze]

Also how many PSI are you running in them?underinflated/overinflated tires can also have similar problems with uneven wear.

[kostby]

Just about every front wheel drive car I've ever owned with a beam rear axle has caused scalloped edges on the rear tires, even with regular rotation. I think it's something about the way the axle moves both wheels together over bumps, as opposed to independent (front and AWD rear) suspension that lets the rear wheels move, duh, independently!

[Sublimewind]

Quote, originally posted by JI737 »So I went this week to get my tires rotated, as normal, and the guy tells me he won't do it, because they are wearing irregularly. He used a strange southern-accented term that I didn't quite understand, but said the front tires were shaped like a seashell (maybe he said scalloped? must have been). So, assuming the front tires are mildly scalloped (I honestly can't see much from my untrained eye looking at it, and at the last rotation there was no mention of it, but the place I got them rotated doesn't do anything but rotation, so I trust the diagnosis), what would you do? Go ahead and get the tires aligned, or is it maybe a shock problem? I'm always wary to pay to fix something that isn't actually the cause...ThanksFeathered? That's what it's called around here... The leading or tailing edge of each tread block is higher/lower than the tread block in front if it.... This is usually caused by toe issues... But most american cars come with some "toe" in the alignment... this is also why the tires need to be rotated... Camber can also wear the edges like that, but it's less likely.. You need the alignment checked, fixed..

[JI737]

Well they aren't the OEM tires, they're BF Goodrich Traction T/As with probably 20k on them, though I don't have my service book with me so that's just an estimate. What he called them was definitely something that started with an s (or maybe a c) so it probably was scalloped or cupped, although the description of feathered sounds about how it was described to me. I think the thought was that if he rotated them and I didn't fix the alignment, then the rear tires would also wear the same way and all of them would be screwed up although I also like replacing all 4 tires at the same time. Whatever the irregular wear was, he said it was "real bad" so whatever changed had to have happened between now and 9000 or so miles ago, when I last got them rotated because the back tires aren't exhibiting the same kind of thing. But it is of note that I'm not really hearing any strange tire noise and the steering isn't pulling at all. I try to keep the PSI around 35 but, honestly, I don't think I had even checked it between the last oil change and when they got seen the other day. I might go take a more-than-cursory look at the tires and see if I can see anything, and probably end up just getting the alignment done. Won't hurt anything, anyway. Thanks for all the great replies.

[jake75]

Potatoes are scalloped, tires are cupped.I have read where bad shocks can contribute to this.

[Sublimewind]

Quote, originally posted by JI737 »Well they aren't the OEM tires, they're BF Goodrich Traction T/As with probably 20k on them, though I don't have my service book with me so that's just an estimate. What he called them was definitely something that started with an s (or maybe a c) so it probably was scalloped or cupped, although the description of feathered sounds about how it was described to me. I think the thought was that if he rotated them and I didn't fix the alignment, then the rear tires would also wear the same way and all of them would be screwed up although I also like replacing all 4 tires at the same time. Whatever the irregular wear was, he said it was "real bad" so whatever changed had to have happened between now and 9000 or so miles ago, when I last got them rotated because the back tires aren't exhibiting the same kind of thing. But it is of note that I'm not really hearing any strange tire noise and the steering isn't pulling at all. I try to keep the PSI around 35 but, honestly, I don't think I had even checked it between the last oil change and when they got seen the other day. I might go take a more-than-cursory look at the tires and see if I can see anything, and probably end up just getting the alignment done. Won't hurt anything, anyway. Thanks for all the great replies.Enter is OUR friend.. lol..Scalloped CuppedFeatheredAll interchangeable terms, meaning about the same thing.. (to the laymen) If you run your hand over the tread of the tire, and they are bad, it will be FAR easier to move your hand one direction, than the other... easy in the direction of the "ramps" Hard in the direction of the "walls"http://www.procarcare.com/incl....htmlh ... .htmYou'll get what i'm saying... Do you have a digital camera? A picture is worth 1000 words.. I could easily be miss-diagnosing on description alone.. lol..