Seems I have the same problem. 13,000 miles and on the second set of tires. I have been dealing with the dealership and Rocky Mountain Truck works (Vanworks) to resolve the issue. The dealership has pretty much washed its hands of the situation. After two alignments and a set of tires, they now say its RMT's problem. They (RMT) installed the lift.
I took it to RMT and the guy I dealt with there (Preston) tried to tell me this is perfectly normal.
Hopefully someone can get their problem resolved and help the rest of us with some answers. Because this is definitely NOT normal....