Anyone had an issue with the transmission auto trans having play in it? With cruise on the drivetrain knocks as well as going from coast to accelerating or vise versa. Very annoying. It sounds like bad u-joints but I checked it on a lift, drive shaft has no play even at the center bearing. it sounds like its either in the trans tail shaft or possibly the diff. Trans mounts are good as well.

 

Check the motor mounts too...

 

Mine does that too if I release the throttle and get back on it. I've checked everything and came to the conclusion that in my case the tailshaft has alot of play I might replace it if it gets worse.