No ball joints if your truck is original. If original, it has king pins. I would first look at spring bushings and U-bolts, then the spring tie bolts (front and rear for all those). The tie bolts are hard to check, but if one is broken, sometimes the spring leaves move out of their normal location. Next, check the king pins and engine mounts. Loose or sagging engine mounts might let the engine move enough to let the exhaust pipe clunk into something, depending on the exhaust pipe/tail pipe routing. Do you notice anything when braking? A loose backing plate will clunk with brake application, forward, then reverse.
Harvester
