here is a tough one (tranny)

[ebpda9]

here is how it starts: i went today to do a tranny oil change, so i jack the car up, remove both of the wheels, so i will run with the car @2500 rpms in every gear to do like a tranny flush. When i was doing this i hear a pretty weird noise comming from the engine bay and underneath the car, so i ask my friend to look at it. He tells me that the engine is moving backwards too much. I ask him to keep the car running at 30 mph while i take a look at the thing. Damn, the whole engine tranny assembly moves backwards so the tranny will bend the driveshaft (from the joint) and then hit it causing the noise. After i drained and refilled the oil in the tranny i ask him to run the car so i can see the thing once again. The tranny won't go back that far now but the right wheel will turn intermitently (1/4th of a turn then stop, another 1/4th and stop). After i let the engine run for 5 minutes the wheel starts turning constantly and no more stops. I looked at the mount of the tranny and engine and everything seems to be ok except the "dog bone" torque motormount. Any ideas what could be causing this ? Any clue how much for the mounts and labor ?