Burnt

Have a 2004 Scion XB, manual tranny. Does one of the front tires consistently wear faster than the other? That is, does the differential NOT allocate power equally to both wheels? Of course, this is irrespective of road conditions and rate of left versus right cornering, etc. On my 2004 Corolla (it's been a while), I could have sworn that the right axle was shorter than the left one (manual tranny), and the right axle also had a rubber vibration damper (I think that's what it was) on it. This makes me think that there may have been a bias in the amount of torque distributed between the left and right drive wheels.

I ask, because three of my tires are at 80% worn, and the fourth is at only about 65%. I'd like to put the least worn tire in whatever front position (left or right) may be known for handling the majority of the driving torque.

So, ways to reply:
1. If there is no torque bias to either left or right on this car, please state so. For all I can tell, both axles are the same length coming from the tranny, and I don't see that rubber vibration damper (?) ring on either of the axles, either. Don't know if that figures in, or not....
2. If you do notice that either the left or right of your front tires consistently wears faster, please state so.

Thanks, peoples!

05sciko

the tires should all wear evenly assuming that your alignment is right. i would start with alignment and see what it says. a negative toe on one wheel could cause the tire to wear because it is basically being dragged along.

Burnt

I appreciate the reply, but this does not answer my question. My alignment is within specs. The cause of my tires being unevenly worn is not the issue, because I bought the car, used, with the tires that way. It was a former courtesy car for a dealership, and they took excellent care of it. If I had to conjecture, I would simply say one of the tires was damaged and replaced some point in from all four tires being new.

Again, I have posted in this category, hoping that someone, who is familiar with the power output characteristics and transmission of this car, can confirm whether one of the front wheels typically gets more power than the other. Or, again, does anyone have the experience to have noticed that one tire simply wears a little faster than the other. That's the information I am looking for.

Reactor

Ever heard of the torque steer? That's when the FWD car tends to move to one side during hard acceleration. So, yes, torque is not distributed evenly but under normal driving the difference is negligible and should not cause big variation in tire wear.
Can you be more specific about what kind of wear there is? Sides, center, etc.? How heavy are you? Regular tire rotations should even everything out anyway.

Burnt

Hey Reactor, EXACTLY. That's what I'm getting at. Under hard acceleration, one of the wheels consistently gets more power. WHICH ONE IS IT?

Keep in mind, the wear on the tires is not the issue. All four tires are consistently, evenly worn across, it's just, as I have stated above, that one of them has more tread than the other three. This is why regular tire rotations do not figure into my scenario. As I said, above, I am surmising that the newer tire was simply a replacement for a failed tire some point in from all four tires being replaced. My question is not concerned with uneven wear patterns, misalignments, driving habits, road conditions, my weight, proper rotations, or anything like that. I don't know how explicitly I need to express my initial questions, but again, what I want to know is which tire is it that consistently gets more torque? Is it the right one, or is it the left one?

Reactor

Disable the TRAC and take off as hard as you can on wet pavement and you will find out.

Burnt

Yep, excellent, good idea. I had thought of checking out in a dirt parking lot (it hasn't rained here for a while, and it probably won't in the near future), but I think I would need an additional observer. I also thought just asking on here would be a first step.

Anybody else want to comment?

05sciko

you didnt state that your alignment was in good order. you asked if one tire would wear faster than the other. and in the case of torque steer your vehicle will lunge in one direction and the other. the reason a tire wears is because the open differential will only put power to the tire with the least amount of "grip" therefore neither side should wear faster than the other. maybe instead of trying to give minimal information on a topic over the internet you should take the vehicle to a mechanic and let them steal your money or... you should be more specific in what you are looking for. noone can help you over the internet with a problem if you leave out key components like your alignment being in perfect spec and wondering why one tire is worn down. btw most courtesy vehicles are dogged badly and not very well taken care of. ive been in the industry for a while and know this for fact. so back to topic.... one wheel will spin under hard acceleration but its not always the same one.

Reactor

That's a good point. But for everyday normal driving on even pavement i think it will be always same wheel that pulls harder than the other. If the length of the axles is the reason, then the driver side would wear more cuz it's axle is shorter.

05sciko

i dont know what kind of logic you used to come up with that idea but its completely wrong. under normal load both front tires have the same amount of force applied. assuming a shorter driveshaft would cause that wheel to have a different ratio is impossible. its like putting a spare tire on the front of a fwd and driving for 5k miles. a different ratio on one side would destroy the transaxle. millions of dollars go into research and development of these vehicles and its completely irrational to think that they would want to destroy the trans because of different ratios

Reactor

No logic. In my first post i said that under normal driving the difference is negligible. If torque steer is caused by the difference in drive axle's lengths then may be the shorter axle will transmit more torque (just my guess).
In my 06 xB the tire wear is pretty even but in my 08 RAV4 the front driver side looks to be wearing faster than the others.

05sciko

still not logical. if you have two dowels that are of different length and both spin at the same speed then both will have the same power and torque at the open ends of the dowel

Reactor

With straight dowels there would be no difference. Don't forget that we have CV joints and axles don't come out straight and at equal angles out of the transmission. http://www.aa1car.com/library/torque_steer.htm

05sciko

even though the ratio of the axles is the same out of the transmission unless there is slip in one side. under normal load slip will not happen and both wheels have equal power. it wouldnt make sense to have different ratios. if you dont believe me ask any CERTIFIED mechanic and they will tell you the same

Reactor

Is there such thing as torque steer? - Yes. Is it possible that same forces that cause torque steer may have contributed to uneven tire wear? - May be. I don't really care about this issue enough to go and ask someone how that theory applies to xB's.

JohnnyBfromPeoria

I have an '05 xB with an automatic transmission. At 145,000 miles, I've not seen any difference in wear on any particular corner with respect to tires.

I would think that a torque bias in straight-line driving could be felt at the wheel, much like torque steer can definitely be felt in some FWD cars during hard cornering under power or during rapid acceleration in a straight line.

My solution to this problem, if it IS a problem...buy four new tires and report back in a year.

John B.

05sciko

i agree

eignub

easiest way to say it, is we dont have a lsd (limited slip differential), so no, it doesnt always apply equal power. i tested to see which tire would slip for me, so coming up my dirt driveway i gassed it, and my driver side slipped while my passenger side rolled normally.