Every time I put my car in reverse after sitting for a day or two, it clunks from the rear suspension, especially if I crank the wheel in either direction. Any suggestions on the source... the car sees a lot of autocross action but the rear suspension is 39k miles of bone stock except for the SLP panhard bar (which i took out and greased the poly bushings thinking it was them).

 

Could be your driveline, check your U-joints or play in your differential pinion gear.

 

Its not when I initially put it in reverse all the time, sometimes it is when the car is moving at a few miles per hour and the rear is under constant load. Its not in the drivetrain... its definitely a body/suspension clunk. Are there coil isolators in the rear? Could the sway bar if the links or bushing are worn cause a clunk but only in reverse? Its hard to diagnose because I cant make the car do it all the time if it hasnt sat for a while.

I have 2 lifted Jeeps... I know what bad u joints are like ... its not them