My rear end has a heartbeat

[moparedtn]

Logic: what has changed since last time all was well (with no "heartbeat")?
Tires and wheels off/on the car?
There's your culprit.

 

[dart6]

Logic: what has changed since last time all was well (with no "heartbeat")?
Tires and wheels off/on the car?
There's your culprit.

Car is new to me

 

[Pecos Bill]

Bent axle flange, possibly, or wheel. Tire making contact with the wheel tub?