I have a 2006 Chevy Silverado. After a complete stop a distinct “clunk” comes from the rear passenger tire. It’s not heard or felt every time maybe 70%. I’ve raised the rear end and spun both tires to check for a sticking caliper. I haven’t removed the tire. Brake fluid is full and in good shape.
Last time I heard a clunking noise from the rear of my 1500 PU, it was the spare tire loose from the underside of the body.
Tired bushing are perhaps the most common cause of clunkerism. Raise the rear end again SAFELY AND SECURELY and start maniacially shaking things like suspension componenets and particularly the sway bar. Post back with the results.