I have a '08 with a 3.5L and a 4 speed (Hate the 4spd!), anyway I was getting the rumble strip effect sometimes when it would lock up in 4th. Dealer reflashed TCM and it went away for awhile. Week later, it came back. They replaced the torque converter and put the car into torque converter break in mode (never heard of such). Now it shutters EVERYTIME it locks up! Dealer says it requires 6 hrs of lockup driving until it breaks in and stops shuttering. Anyone experienced this? Im very frustrated and cant even drive the car normally!!