I HAVE 2002 F150 FX4 SUPERCREW w/ a 6" fabtech suspension lift & 3" body lift w/ 38" Toyo MT tires. I also have my gears changed to 4.56. The problem I have is that when im in over drive doing around 55mph and give it gas it downshifts and makes a chattering noise for a second or 2. Only happens when in overdrive. Anyone know what the problem could be?