Something sounds wrong. I have a 2wd and have never had a problem in half a million clicks. My rotors are original and I have never had them turned even once. I wonder if there is an axle and/or bearing problem contributing to your woes. I know there are some fancy pads which reduce heating and are said to be better at resisting warping. My brother put some on his Hemi and loves them. Sorry I can't remember anything more specific about them.