Re: rear tires cupping on the inside
[quote author=wolph69 link=topic=148367.msg3187556#msg3187556 date=1245457406]
This is my second brand new set of tires. First cooper tires, not Bridgestone tires. I replaced the coopers because they got so bad my steering wheel shook after I rotated the tires from the back to the front. I rotate every 3k miles to try and avoid this so all 4 end up getting bad cupping. Now the bridgestone stires are doing the same thing and ony on the rear... both sides passenger AND driver. I have had an alignment every 3k miles ( I know it's overkill but I wanted to make sure) and had the toe set to 0 on all 4 corners. I don't know where to go from here. Any suggestions on why my tires are getting cupped after only 10k miles? I've heard bad shocks in the rear can cause this but i've checked them and they are fine. Any ideas?? I love this car, but if I can't find a cause to the tire cupping I'm going to have to trade it. I drive for work so 10k miles is about 3 months. Also, car is stock. It's funny because you can see the wear on the rear tires they doin't seem to be even touching the road on the outside of the tire. Can too much Camber cause this?? It is well within mazda spec at about a degree.
Myself and others have had the exact same problem. I've had 3 sets of tires in the back. So far it's happened to the first two after thousands of miles of driving, say 10K. When it feathers, it's also accompanied by a noisy hum. This is partly why I don't rotate the tires since I don't want the noise at all 4 corners.
On my 2nd Yokohama S.drive set, you could actually see that on the inner tread, they alternated in darkness. Black, dark gray, black, etc as if every other tread block wasn't touching the ground and just getting dusty.
Many drivers here say rotation is key but as we've experienced, it doesn't help, just eventually creates more interior noise. Nobody really seems to know or have had it resolved. I suspect toe, but you stated yours is zero'd out. Others have stated negative camber, but in my experiences with other cars it just causes the inner tread to wear out much faster.
Never had the car aligned since I bought it in '07, since the tech stated each time that the car is within spec. Factory specs are a little generous though so I may take it to a shop with higher standards. I have 60K miles and the shocks are still good via the bounce test.
Hypertech MESPP, Aasco lightweight flywheel, Medieval lightweight pulleys, 60mm throttle body, track pipe, Cosworth air filter, OEM BBK (Ms3 front & Mz5 rear brakes), Endless pads/DBA rotors, Koni FSD, OEM '04-06 16" Mz3 alloy wheels, staggered Continental ExtremeContact DW (225/50/16 front & 205/55/16 rear), Morimoto/Xtreme/Lamin-x HID 5,000K headlights & 4,300K fog lights, OEM LED tail lights, OEM leather seats, OEM JDM leather armrest, Eneos 5W-20, Amsoil 75W-90 GL-4, ATE Super Blue