My rear driver side wheel is tucking when I coast or turning and accelerate under 20mph. Can someone give me a idea of what it is? I've taken the wheel and there's nothing. It sounds like a tick with like metal to metal and I'm not sure what it could be. HELP!

 

Lift up the rear and spin your wheel. Does the noise get faster the faster you spin the wheel?

If you have disk brakes I'd put money on either your slide pins. Take the pins out, clean up and lube them.

 

See if the emergency drums have come loose and are flopping around inside the rotor