2000 Chevrolet Tahoe clunking in rear end

Clunks and rattles are never a sign of something good but in general, when they're coming from the rear it is typically less serious than from the front. First look for a loose spare tire, then worn or broken anti-sway bar links. Other common suspects include loose straps around the ends of leaf springs, worn shock absorbers or their rubber bushings, and loose or broken tail pipe hangers.

For elusive clunks an inspection at a tire and alignment shop is in order. You may also be able to find a "Chassis Ear" at an auto parts store that borrows tools. That is a set of six microphones, a switch box, and head phones. You clip the microphones to suspect points, then switch between them while driving and listening to the head phones. You can zero in on the source of the noise by moving the microphones around.