Originally Posted by allan5oh

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.

Originally Posted by ralcotruck

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!!!

Originally Posted by tracer

So, are you saying that using wrong size tire on steers shouldn't cause the drift by itself? I mean, if the truck came from the plant with 295s on steers, and the previous owner changed them to regular 11R22.5s ... are you saying IT SHOULDN'T AFFECT THE STEERING by itself?

By the way, while I was looking for the "cure" for that drift, I did ALL WHEEL alignment not once but ... twice. I even went to Shop #1 and asked them to do another custom alignment and increase my caster ... The guy did what he could, but nothing had changed. Only when I put on 275/80R22.5 Michelin XZA 3 on the front, the steering improved dramatically - no more drift. But from what you're saying, it's not as simple as changing the tire size back to the factory?

Originally Posted by tracer

So, are you saying that using wrong size tire on steers shouldn't cause the drift by itself? I mean, if the truck came from the plant with 295s on steers, and the previous owner changed them to regular 11R22.5s ... are you saying IT SHOULDN'T AFFECT THE STEERING by itself?

By the way, while I was looking for the "cure" for that drift, I did ALL WHEEL alignment not once but ... twice. I even went to Shop #1 and asked them to do another custom alignment and increase my caster ... The guy did what he could, but nothing had changed. Only when I put on 275/80R22.5 Michelin XZA 3 on the front, the steering improved dramatically - no more drift. But from what you're saying, it's not as simple as changing the tire size back to the factory?

Originally Posted by tracer

Did search online for "wheel alignment". Found an interesting article, which says this about CASTER

"Caster is the tilting of the uppermost point of the steering axis either forward or backward (when viewed from the side of the vehicle). A backward tilt is positive (+) and a forward tilt is negative (-). Caster influences directional control of the steering but does not affect the tire wear and is not adjustable on this vehicle. Caster is affected by the vehicle height, therefore it is important to keep the body at its designed height. Overloading the vehicle or a weak or sagging rear spring will affect caster. When the rear of the vehicle is lower than its designated trim height, the front suspension moves to a more positive caster. If the rear of the vehicle is higher than its designated trim height, the front suspension moves to a less positive caster. With too little positive caster, steering may be touchy at high speed and wheel returnability may be diminished when coming out of a turn. If one wheel has more positive caster than the other, that wheel will pull toward the center of the vehicle. This condition will cause the vehicle to pull or lead to the side with the least amount of positive caster."

That answers why my truck improved steering with 295 tires! It was designed to use shorter tires, and then Owner 1 put on taller 22.5 tires. When I reinstalled the original 295s (smaller radiius), the caster changed back to normal because the truck was sitting lower, the way it came from the factory. Eureka!

Originally Posted by tracer

Did search online for "wheel alignment". Found an interesting article, which says this about CASTER

"Caster is the tilting of the uppermost point of the steering axis either forward or backward (when viewed from the side of the vehicle). A backward tilt is positive (+) and a forward tilt is negative (-). Caster influences directional control of the steering but does not affect the tire wear and is not adjustable on this vehicle. Caster is affected by the vehicle height, therefore it is important to keep the body at its designed height. Overloading the vehicle or a weak or sagging rear spring will affect caster. When the rear of the vehicle is lower than its designated trim height, the front suspension moves to a more positive caster. If the rear of the vehicle is higher than its designated trim height, the front suspension moves to a less positive caster. With too little positive caster, steering may be touchy at high speed and wheel returnability may be diminished when coming out of a turn. If one wheel has more positive caster than the other, that wheel will pull toward the center of the vehicle. This condition will cause the vehicle to pull or lead to the side with the least amount of positive caster."

That answers why my truck improved steering with 295 tires! It was designed to use shorter tires, and then Owner 1 put on taller 22.5 tires. When I reinstalled the original 295s (smaller radiius), the caster changed back to normal because the truck was sitting lower, the way it came from the factory. Eureka!

Originally Posted by bob h

you had 1 bad 11R, if you had swapped them side to side, the PULL would have went away... IMO.

Originally Posted by tracer

both steer tires were brand new Michelin XZA 3. you think one tire was defective? and the pull with 11R22.5s was not to one side, it was to whatever side the arch in the road was pointing too. If I was in the left lane, and the highway sloped left, the truck would go left. If I was in the right lane, and the slope was to the right, the truck would go right. ON a perfectly flat road it would stay put and continue in a straight line.