1998 ford f150 5.4 seems like something is holding my truck back when i am taking off and when i get up to speed and let off the gas pedal it slows down real quick like your foot is on the brake I don't hear anything scrubbing like the breaks.

 

sounds like a compression problem either the head gasket is leaking or the cylinder walls have excessive clearance from the piston

 

The brakes may be dragging or the tranny is screwing up.

 

^X2. Rolling resistance is up. Has absolutely nothing to do with compression, if compression is low so is the engine braking.

 

I don't mean to ask the obvious but your e-brake is not on is it?

it sounds like a brake issue. I would start there before you go tearing into your tranny.

 

Also check the rear end fluids. You can jack the back of the truck up and put the truck in neutral and turn the rear tires by hand see how much resistance there is.

 

This was my first thought while reading the thread.

 

X3 on the E-Break not releasing all the way...does it do it in Neutral ?