Anyone ever heard of a pre-97 popping when the terrain causes a truck to torque? My Dad had this problem, which usually happened when he pulled into my driveway. Just a slight incline, with the wheels turned sharply, a very loud single pop occured almost every time. He replaced several rivets with bolts, thinking it was the problem. After this didn't work, while walking beside his truck while he was pulling into my driveway, i localized the noise to the lower fender.

The problem turned out to be the front left fender was popping, and after he loosened and retightened some bolts, the noise was gone. Thought maybe this would help someone out there. His is a 96 f250 2wd.