Clunking in suspension replace most everything.

Absolutely, and it's easy to tell. At the rear it is attached through rubber bushings to a piece of angled steel welded to the frame. Under the nut is a large steel washer on the back side. Look at the paint on the metal near the edge of that washer. If it is rubbed off or there's a rust spot there, the washer has been making contact and causing the rattle. Replacing the bushings will solve that.