Originally Posted by Cottonfarmer
Wonder why the back tires wore unevenly like the front tires? That doesn't make sense to me. I am suspecting these cars are easily knocked out of alignment from potholes, curbs, etc. and that a religous check on unusual tire wear needs to be made at regular intervals.
I'm throwing a few things into the blender in figuring out what's going on. First, the Monaro was never meant to have this much tire. If I remember right, they were originally designed to have 215s. The 17-inch rims are shod with 245s, which pretty much max out the wheel wells. Up front, that fat tire--even when aligned properly--is darned close to the strut, even when the car's sitting still. No telling what happens under compression or in cornering.
Second, these cars are heavy. 3,700 pounds will do a nice job of compressing an independent suspension. If you look down the side of your GTO, you'll see noticeable negative camber (tip-in at the top) on both front and back wheels. Negative camber equals more wear on the inner tread rib. That could
be why your friend's rear tires also exhibited such wear, but assuming he's had his tires rotated at least once, I'd bet that a good portion of that wear came when the rear tires were up front.
Third, hard acceleration and cornering (which of course we never
do in our GTOs) take their toll.
As for the alignment being easily knocked out of whack, I don't know. That certainly could be part of it.