You have defective shocks. There is no other way all 4 tires can be
cupped.

Mike
86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
88 Cherokee 235 BFG AT's

Helvis wrote:
>
> I took my Ranger in for an oil change and tire rotation at Meineke. It has
> 13,400 miles on it and is 2WD. It had 18 miles on it when I got it from the
> dealer.
>
> This was the first time that I had the tires rotated. I'm sure it was over
> due but I didn't think it was by much. The mechanic called me out to the
> garage and showed me that the all 4 tires were cupping and said that it was
> because of defective shocks. He said that the front tires were the worst
> but the back tires were in trouble too. He knew that it didn't have many
> miles on it and suggested that I raise hell with the dealer to have the
> shocks replaced before it ate up my tires any more. He did rotate them left
> to right so as to leave the better tires on the back for traction.
>
> I called the service desk at the dealer and he told me that the cupping
> would not be caused by bad shocks and that it had to be because of
> misalignment or lack of rotation. He said that the front wheels had to be
> misaligned and the back tires had been rotated so they were also showing the
> wear also. I know that this is not the case since they had never been
> rotated before.
>
> So here are my questions to you guys:
>
> Do bad shocks lead to cupping?
>
> How does lack of rotation cause cupping on the back tires when it has a
> fixed axle that needs no alignment?
>
> Thanks in advance for your opinions.