hey guy's, 2005 5.4 4x4, 92000 miles and not a problem until now... tranny seems to shutter when excellerating in over drive between 40 and 60mph, no lights have come on and all else is fine, took it to a tranny shop today and they took it for a ride and said that the torque converter was bad and needed to be replaced @ $700.00. Anyone have seen this problem before? also hear that if the engine was off a little this could mimic tranny problems??? Gonna need new plugs soon, could this be the cause?? hate to buy a part that I don't need. Any help would be great!! Thanks...