[TR] Backward jerk goes forward

[Mike Newhart]

Took my driveshaft off and had it balanced with new U-joints.  That wasn't
the problem.  Still jerking forward when I go backward.  Jacked entire car
up, and the rear brakes aren't binding.  When I put the 3 in gear on stands,
the rear right wheel had a horrible wobble, even after trying 3 different
wheels.  Loud clicking sound, and some noticeable play.  Is it axle?
Differential?  Any thoughts are appreciated.  Thanks, Mike Newhart
Mike at newharts.com