[Boss Hoss]

You are running stock size tires and many people run 20's so you dont have an oversized tire issue. Perhaps the rockstars have a different offset which my cause problems. At any rate if you truly have a problem im confident it would be covered under warranty. You may be better served to take it to a local shop for a diagnosis prior to making your journey to the dealership(if it is bad enough to cause concern). You also may want to check out Proctor as they are better equiped for the more discerning owner(you feel like you bought a 65k truck when you go for service).