I am not sure what the problem is, but here goes the best explanation I can manage. When driving the truck at say about 30-40 mph, and just barely pushing on the gas, the truck will jerk almost as if the transmission is trying to switch back and forth from OD to the lower gear. If I disengage the OD, rpms go up and it stops. If I reengage the OD, it starts again. If I accelerate, it doesn't happen. It doesn't happen at low speeds or higher speeds than about 45 or so (from my recollection). So lets say I get up to about 35-40 mph, stop pushing the gas, then ever so slightly push the gas, it starts again. This problem is relatively new, starting months ago. By the way, I have a 2004 F150 Lariat 4x4 triton 5.4 towing package
thanks for the help..
Paul

 

It is almost certainly a bad ignition coil. I've fixed many of these with identical symptoms.

 

Its either a coil or a plug with carbon tracks. Find out which cylinder it is and replace the coil and plug on that cylinder then replace the rest of the plugs and coil boots.