Left Rear Tire Wear

Well, I can't say that I've heard of this one before. So, about a month ago I had a chunk come off the inside band of my driver-rear tire on my nice 17" rims. I scratched my head, looked around inside the wheel well for anything obvious that could be hot, touching the wheel... whatever. All I notice is the little plastic mud-flat type thing in front of the tire is cracked and is kind of flapping. So, I figure when the tire chunked and started whacking around it hit that. No big deal. I just broke the flapping thing off, put on my 14" factory wheel set and figured I'd just replace the expensive tire when I have a few bucks down the road.

Well, today I started noticing some pretty serious wheel vibrations at 65mph. So, I just slowed down and got it home to check it out. So, I pull the left rear tire off, and whaddaya know... inside two rows of tread, again, worn out and out of whack. The tire won't stand up on it's own because the inside rows are bubbled up like it's way over inflated. So, again, I look around the wheel well for anything that could be causing trouble. All I notice is there seems to be some moisture around the inside edge of the wheel well. So, I look around and look around. The ONLY thing I find there is... what appears to be the gas tank pressure blow-off tube in front of the wheel well, in line with the inside rows of tire tread.

Now, this just plain doesn't make any sense to me. Yes, it's 100 degrees here. And yes, there have been a few days of serious tank pressure build up. But, I can't believe there would be anything solid coming out of there that would eat the tire up. Just vapor if anything, right??

Anybody have any ideas? Cause I'm completely at a loss here. I don't see any oil leaks under the car from the motor. I do have a power steering fluid leak up front, but that's a little more towards the center of the car, and I don't think that really gets hot or anything. All I see is me spending money on a tire that could, conceivably, just get wasted in 5k miles or so, and I'm pretty baffled.

Sounds more like an alignment issue when was the last time you had it aligned?

Any pictures?

+1 on alignment. Likely the rear toe it out of whack (literally, toe-out wears the inside edges).

Well, now that I'm calmed down somewhat, I will agree that it's probably an alignment thing. Being extremely poor and pretty much out of work since mid-december, anybody know a relatively inexpensive yet trustworthy place to have it done? (while I'm at it, know where I can find a Unicorn?)

Or, a reasonably logical way for me to try to do it myself? I know, it's crazy but really... times are tight. When I say tight, I mean like a mouse in a python.

Ideas?

Find someone with a camber gauge and toe plates.

Or use the string method (google it). Assuming you have some strings and jackstands you can do it that way. I'm not sure how the Miata's rear toe is set though.

Your left toe is way out. Google for how to measure it.
Align it yourself, good luck.
Find an after hours hookup for alignment.
I think Brakes Plus will align it for $50
Sell the "17 or "14 wheels and get it aligned or keep buying tires.