Here lately i've noticed that when I go to pass a car on the highway running 55-70 in overdrive that when I sink the pedal to the floor my truck winds up and then makes a really loud thump and the truck jerks really hard before speeding up. The feeling/sound is about like doing a neutral drop and is horrible. It only does it in overdrive when the tranny drops down 2 gears. Does anyone know what might be wrong with my tranny or does anyone think my tranny is messed up? The truck has right at 45,000 miles on it. Any help is appreciated.

 

anyone?