The front passenger side tire on the wife's Yukon is wearing unevenly, wearing worse on the outside, why is this? All other tires appear to wear fine. Is it just that the tire is not balanced correctly or could it be a wheel bearing issue?? Thanks for any help you can give. I figured since I drive an 05 GMC 2500HD CC SB D/A it would be ok to ask a question about the Yukon, lol.