2002 mustang GT 5-speed, 43k. I recently took my car in to have the transmission looked at because of a grinding into 3rd gear at mid to high rpm when the car is warmed up. They told me there was a technical service bulletin out for this problem and the proceeded to replace the synchros, forks and some other parts that escape my memory right now. I got the vehicle back and its still doing pretty much the same thing. The dealer told me there would be a 400 mile break in period but i didnt think the grinding would reoccur. Its like when its cold the gate is working well to stop me from going into third until the synchros readjust the speed. But when it warms up it feels like there are no synchros at all just goes right into third with a grind. Should I try a diff. tranny fluid, i've read that works miracles for others, synchromesh maybe? Or is it a clutch problem?, Shift linkage? Please Help?...Please dont reply if your going to say its my driving, I've been driving 5-speeds for many years and am fully capable of good solid shifts, Thanks for your help!