I fixed a similar problem on by 07 GT several years ago. There's a TSB (don't know the number, but it dates back to 05-06) that prescribes removal of the exhaust hangers located at the transmission mount cross member. These hangers are used during manufacturing assembly to hold the pipes in position for mating with the forward section, and serve no purpose after that. All you have to do is remove the hanger caps thst contain the rubber insulators. I cut through them with a hacksaw to facilitate removal. The insulators aren't very sturdy and allow the pipe that they support to contact surrounding metal and translate vibraion to the shifter mechanism.
Last edited by illini4; 12-24-2013 at 12:28 PM.