I have a 2005 mustang gt with 130k miles. Ford performance driveshaft, Hurst shifter, tune and a few other goodies. Last December I had my car on the dyno and right after it was a little harder to shift. Over the last few months it has been completely random whether it will be hard to shift or not but in the last two weeks, it is consistently only when the transmissions heats up. 3 months ago I changed the transmission fluid for valvoline mercon V at, the fluid that came out didn't look...

Transmission issue