I recently replace the torque rod and track rod bushings on an 87 745 w/V8 conversion. All was well for about a month until I gave my two teenagers "stickshift" driving lessons -- after a number of stalls, burnouts, and drive train whiplash starts, the car said uncle and developed a loud clunk on acceleration and decceleration. Stopping the car and leaving it in gear, the clunks could be duplicated by pushing on the car. Observing the subframe it would move forward and back into the bushing during the clunk. The drive shaft u-joints are less than 60 k miles old and appear to be in good shape. I assume that the frount mount of the subframe is designed to move in and out on the bushing, which leads me to ask what woreout/broke, was incorrectly installed, or needs to be replaced? Any thoughts?

Thanks, Pete