Lee, this is torque, the transmisison mounts are rubber as not to transfer vibration to the frame and make for an uncomfortable ride, when you accelerate or brake the drivetrain torques and would shift a little back and forth, If it was my car I would jack up and inspect the mounts, tighten them and be good to go.

__________________
Jerry

2004 SL500 Black 55K Miles
2002 s500 Black 90K Miles
1986 300E Gold 233K Miles
1966 Twin Cessna 320D
1989 Jeep Cherokee 233K Miles
1994 Ford Van E150 399K Miles