On a solid rear axle?
After doing some research, I can see why you’re asking that question, but that is what the wear pattern is telling us if the tires weren’t rotated from the front.
The camber being out of specs won’t wear out a tire in 15,000 miles and it would be difficult to bend the axle housing that far and still be driveable. The toe only needs to off by a few degrees to quickly wear out the tires and the axle housing can be bent causing the toe value to be off.
Possible, definitely worth checking the toe also. But when I’ve had toe-in problems on my truck’s front wheels it creates unusual wear patterns across the entire tread width, including at the outer edge. The tread appears to be sort of roughed-up.
The tire wear pattern has to be considered in context with all the other factors. If by some miracle an axle housing of this design were to get bent, the differential would almost immediately self destruct. Alignment of the carrier housing would be forced all out of whack and would take the alignment of the spider gears, the ring gear, and all differential gears and bearings out of whack, also introducing operating stresses that they’re not designed to survive. These adjustments are critical to the level of making differential repair an expert level job.
I’m going to stick with the low tire pressure theory. That would cause the outside tire in a turn to “roll under” more than normal, and that would cause extra wear to the outside edges.
Note that the differences across the tire are really minimal. The entire tire is well worn.
Looks like we’re making similar observations and supposing a similar hypothesis.
I wouldn’t know a Toyota 4runner from a UPS truck. I’m not sure what they look like or what size they are.
“Around 32psi”. What tire pressure is specified?
My dodge Caravan specifies 35psi on all corners. It actually seems to like 36-37psi better. I know for sure that 32 would be way too low on my Caravan.
[quote=“common_sense_answer, post:26, topic:108726”] … “Around 32psi”. What tire pressure is specified?
My dodge Caravan specifies 35psi on all corners. It actually seems to like 36-37psi better. I know for sure that 32 would be way too low on my Caravan. [/quote]
Yup, the pressure specification for a 2002 Toyota 4 Runner with P265/70R16’s is 32 psi. (according to Tire Guides). Interestingly, the pressure spec for the standard P225/75R15 is 29 psi!
I suspect the tires were never rotated on this car.