I wanted to put this out there even though it's an old thread. I had a loud bang/ pop coming from front end loaded around corners, left and right turns. Replaced everything. Bushings,pins, rear hangers, bearings, king pins, u bolts etc... still same problem. Ended up being the leafs moving . It had leaf clamps just outside of the u bolts but none out by the hangers where it went down to 4 or so leaves. I made some brackets , no more bang and it was bad . Felt like the tire was going to come off. Same sort of thing on the back and it was the steel centering pins in the rubber pads that hold the ends of the leaf springs. Hope this helps someone. 1999 Mack RD 688s.
