1997 Chevy Tahoe clanking noise coming from the rear

So my car has this clanking noise coming from the rear of the car. Whenever I accelerate the clanking gets faster. When I step off the gas the clanking will get louder for a couple seconds the get really soft. The clanking noise gets faster as the car is moving faster. If I am stopped and I rev the engine there is no clanking which means its not coming from the engine. Aslo when I am moving very slow without giving it gas at like 1-2 mph you can feel the car lurch forward just a bit at regular intervals. Any suggestions? Thnx