Tire wear question

[outback_97]

 

<- Outside Inside ->

 

So, what typically causes this inside edge wear... negative camber, toe out, something else? It's the rear driver's side tire on our Impreza wagon. PSI around 32 in front, 31 in rear last I checked, so I don't think it was underinflation. The tires are about spent, planning on putting snows on in a few months (or as needed) and getting new tires for these rims next year. OTOH they did just fine on our recent 3200 mile road trip... except on gravel roads

 

Steve

[Manarius]

Too much negative camber looks like to me.

[tcspeer]

It looks like the toe is out to me, probably started on the front and once the wear patten got started it just continued to wear. But I dont know if that is the correct term for this problem, its just what I call it.

 

<- Outside Inside ->

 

So, what typically causes this inside edge wear... negative camber, toe out, something else? It's the rear driver's side tire on our Impreza wagon. PSI around 32 in front, 31 in rear last I checked, so I don't think it was underinflation. The tires are about spent, planning on putting snows on in a few months (or as needed) and getting new tires for these rims next year. OTOH they did just fine on our recent 3200 mile road trip... except on gravel roads

 

Steve

[dmanaenk]

toe out or extreme camber. Is camber even adjustable on the rear on this impreza? I thought not.

[tcspeer]

After looking at a tire site, it looks like you have the right word with camber. I have always thought it was toe.

Too much negative camber looks like to me.

[Virrdog]

The picture is not perfectly level, and it would take a monstrous amount of negative camber to wear like that. Toe will eat up a tire much quicker than even a significant amount of camber.

 

Hit any curbs or has anyone done anything to rear lateral arms?

[RallyKeith]

I agree with the assesment of too much toe that may have started the tread wear pattern in the front and then been transfered to the rear during a tire rotation. Toe is when the tire points in or out instead of straight. Camber is the tire leaning into the car or away from the car.

 

Unless your car has been in an accident, or has bad springs or bushings(or overloaded with cargo) it's really hard to get too much negative camber in a Roo. Also, there is no way to adjust the toe in the rear of the car, which is why I'd agree it might be a carry over of the wear pattern after the tires were rotated.

 

Also, that tire IS spent. Notice the lighter grey areas on that portion of the tread. That is a sign that it is about to hit the metal cord. That can be very bad. I'd start by getting a 4wheel alignment and then new tires. Last time I checked the subaru dealer was actually very reasonable on the alignment.

 

 

Keith

[outback_97]

Thanks for all the quick and informative responses everyone.

 

Most likely I'll put the winter rims/tires on sooner than originally planned. Then I can wait until next year to put some fresh tires on these rims. An alignment is probably also a good idea.

 

The picture doesn't represent the orientation of the tire, visually the wheel doesn't have noticeable excessive neg. camber. I don't believe it's adjustable on the rear of these cars. Struts / springs seem fine and this car only has 29K miles. I'm not aware of any impacts with curbs or potholes, etc, but it's my wife's car. She hasn't mentioned anything and is actually quite car savvy and a very good driver, not one to run into curbs at all... plus it's the driver's side, not the usual suspect for hitting curbs. But stuff happens.

 

It could have started on the front as suggested, as far as rotation... I admittedly don't do a great job of keeping track of where the wheels were when I take them off in the fall, when they get put on in the spring the two with most tread go on the front. We put these on this spring and have only driven 7000 miles or so on them, half of that in the week and a half long trip I mentioned. On that trip the car was loaded down with a lot of luggage, gear, cooler, etc. Maybe the trip did it in, with that many miles loaded down. We didn't have excessive weight onboard, but much more than usual to be sure.

 

http://users.sisna.com/ignatius/subaru/tire3.jpg

http://users.sisna.com/ignatius/subaru/tire1.jpg

 

Note the other photos show more even wear, although they're not far from the one shown above in that there's very little tread depth on the inside edge. Part of that is the design of the tires.

 

C/N: These tires will be "retired" from service, winter set on soon, new ones for next spring, plus considering an alignment. Thanks!

 

Steve

[cookie]

wear on tie rod ends often give you too much toe. I'd check for play.

[johnceggleston]

unless there's something wrong with that wheel, you better get an alignment. otherwise you'll wearout your winter tires in the same way. that would be a real waste. you need to solve the problem as soon as the winter tires go on, if not before.

 

 

Thanks for all the quick and informative responses everyone.

 

Most likely I'll put the winter rims/tires on sooner than originally planned. Then I can wait until next year to put some fresh tires on these rims. An alignment is probably also a good idea.

 

The picture doesn't represent the orientation of the tire, visually the wheel doesn't have noticeable excessive neg. camber. I don't believe it's adjustable on the rear of these cars. Struts / springs seem fine and this car only has 29K miles. I'm not aware of any impacts with curbs or potholes, etc, but it's my wife's car. She hasn't mentioned anything and is actually quite car savvy and a very good driver, not one to run into curbs at all... plus it's the driver's side, not the usual suspect for hitting curbs. But stuff happens.

 

It could have started on the front as suggested, as far as rotation... I admittedly don't do a great job of keeping track of where the wheels were when I take them off in the fall, when they get put on in the spring the two with most tread go on the front. We put these on this spring and have only driven 7000 miles or so on them, half of that in the week and a half long trip I mentioned. On that trip the car was loaded down with a lot of luggage, gear, cooler, etc. Maybe the trip did it in, with that many miles loaded down. We didn't have excessive weight onboard, but much more than usual to be sure.

 

http://users.sisna.com/ignatius/subaru/tire3.jpg

http://users.sisna.com/ignatius/subaru/tire1.jpg

 

Note the other photos show more even wear, although they're not far from the one shown above in that there's very little tread depth on the inside edge. Part of that is the design of the tires.

 

C/N: These tires will be "retired" from service, winter set on soon, new ones for next spring, plus considering an alignment. Thanks!

 

Steve

[jamal]

I agree with the assesment of too much toe that may have started the tread wear pattern in the front and then been transfered to the rear during a tire rotation.

 

Unless your car has been in an accident, or has bad springs or bushings(or overloaded with cargo) it's really hard to get too much negative camber in a Roo. Also, there is no way to adjust the toe in the rear of the car, which is why I'd agree it might be a carry over of the wear pattern after the tires were rotated.

 

Most Subarus have adjustable rear toe. My rear lateral link bolts are cammed.

 

And yeah, it's definitely more of a toe issue than camber. You could run -3° of camber and not have that much wear if the toe was at 0.

[Virrdog]

unless there's something wrong with that wheel, you better get an alignment. otherwise you'll wearout your winter tires in the same way. that would be a real waste. you need to solve the problem as soon as the winter tires go on, if not before.

I second this motion. One of your wheels is WAY out of whack in the toe department and will chew up your soft compound snow tires in double time. All wheel alignment should be first on your list unless you have a large supply of tires to go through.