Welcome to the world of what's amada with your brakes. I have had the brakes turned twice and replaced once on 3 seperate visits. I am now awaiting the new brake kits and I only have 11K on '04 Armada. I have only towed my boat once so I know that's not the issue. But there are several people who have had the issue and tire size has nothing to do with it. It's undersized rotors that are heating up and warping prematurely. Visit your local dealer and he'll add you to their "list". I just hope this new kit is better than the last kit.