Good tire, Bad tire
 

Here's a small table that sums up the differences between my Bad Tire and the Good Tire. If anyone has any idea on why the truck was pulling towards the ditch when the Bad Tires were on, pls let me know. When I put the Good Tires on, the truck's steering became perfect (all-wheel alignment was done twice when the Bad Tires were on).

BAD TIRE
Michelin 11R22.5" XZA-3
Diameter: 41.3"
Loaded radius: 19.3"
Sidewall: 9.4" (41.3 - 22.5 / 2)
Width: 11.1"
Weight: 117.7 lbs
RPM: 502

GOOD TIRE
Michelin 275/80R22.5 XZA-3
Diameter: 40.1"
Loaded radius: 18.6"
Sidewall: 8.8" (40.1 - 22.5 / 2)
Width: 10.9"
Weight: 112.9 lbs
RPM: 518

I think a steer tire's width is the factor that affects truck's steering. Weight is probably important too. My original factory size tire was 295/75R22.5

When an all-axle alignment is done properly, and the vehicle still has steering pull, a tire is usually to blame.

Are you thinking that you had a bad tire? ...or, that 22.5s are bad tires?

No, the tire was fairly new and in perfect condition. I just call it "bad" because it caused the truck to drift towards the ditch, while the "good" tire cured that. The guy who did the all wheel alignment wasn't able to explain this curious effect of the 22.5" tire on the truck's behavior on the road.

when a belt breaks in a tire, it will cause pulling problems, it will usually pull to the side opposite of where the bad tire is, no amount of alignment or balancing will fix it. it's possible you had more than one bad one, but not likely, one separated tire can cause a lot of trouble

also, the tire your truck calls for is a low profile.. your "bad" tire is a regular height, the wrong tire can affect performance too. they recommend a certain size for a reason

p.s, for those who say " what do you know?") I was service manager at a truck tire service center for 3 years

I agree with the two posters above. It's not the size difference. It's possible the other tire hit something and damaged it. XZA3's are the best steer tire out there IMO. I usually get 240,000 to 250,000 miles out of them. Right now I'm at about 180,000 miles and there's absolutely NO funny wear whatsoever! I think the shallowest point I could find was 8/32's.

Anyone know why my drivers side tire seems to have a little more rubber on it? Both were changed at the same time.


I assume yours were as well tracer.

it's normal for the tire on the high side of the road to wear a little faster.

When both of the steers tires are the wrong size tire (11Rs instead of 80series), it may affect steering feel, handling, etc... but, it should NOT cause directional pull on its own.

I have seen brand new tires installed that have radial pull... the size or aspect ratio has nothing to do with it.

A competent alignment tech would have recommended that you swap your steer tires side to side to see how this affects your pull; it will usually be eliminated or pull slightly towards the center line. Then, you will KNOW a tire is the cause.

a defective tire usually separates when it is pretty new, people think it cant be the tire it's new, but that's when it happens, I agree, swapping them from side to side would tell you right away

This is 100 percent accurate. I own a repair shop that specializes in truck and tractor alignment. Several things can cause a pull or drift, only one of which is the tire. When your truck was aligned, did you have all three axles checked and aligned? Rear axle thrust or geometric angle depending on which alignment company you bow to can cause inner and outer tire wear on the STEER axle and can cause the truck to push to one side or the other. A difference of more than .5 degree on the caster value on the steer axle will cause the truck to drift or pull to the low side caster reading. Even a dragging brake or wheel bearing can cause the problem. Step one is to make sure that all of the above or ok. If all is in check, rotate the tires and eliminate them as the problem. Many, Many, Many times I have performed a full alignment and after verifying that all of the readings were good, rotated two brand new steer tires to correct or "better" the pull or drift.

Optimum tire wear on over the road trucks is 125,000 miles for the steers and 250,000 for the drives. I am getting 150-175 on steers and 275-300 on drives, with regular maintenance and rotation. Alignment and full balance works-it just needs to be maintnaned. For example, as one of the upper posts says, the left tire is the lead tire, it will wear quicker than the right. Rotation and balance will extend the life of that tire. Tires are way to expensive to waste!!!