I have a 2001 f150 4wd with 5.4lt engine. the transmission seems to be slipping but i am not sure. when i back off of the accellerator and coast for a moment or two and then apply the gas is bucks or jumps a little like i am on a rough road. what does this sound like all of you?

 

My '98 was doing that and I actually took it to an indy mechanic who happens to be a certified Ford tech, gave him 2k dollars for a new tranny, went on vacation for a week.
When I came home, I went to pick up the truck, and he gave me my keys and 1900 dollars back. He said he changed the plugs and wires, and the problem went away ! Check your plugs and wires.

 

I replaced the trans filter and it is still doing it. Basically it feels like it is lunging or shuttering in D but it stops when i put it in N.
could this be the torque converter?

 

I had the same thing happen, complete tune up and tranny flush with new filter and it feels like I got a new truck! (97 4.6 Lariat)