Recently the f150 has started bucking real bad whenever its in overdrive only when it starts to get a little bit of a load on it. My buddy who is a mechanic is going to look at it this weekend and he thinks its a vacuum leak because i'm not getting any warning lights. I figured I'd throw it out here and see if anyone has any other ideas. Its a 03 with the 5.4 with about 80k miles on it.

 

I too would suspect a vacuum leak. Also when I had my tempo it bucked sometimes, even stalled a couple of times. Turned out to be a clogged fuel filter. You could try changing that? It wouldn't hurt anyway

 

Fuel filter isn't a bad idea, but I would think that would give me a continuous issue no matter if it was in OD or not. Then again the truck has been sitting most of the last 2-3 years due to my dads illness. Its maybe had 10k miles put on it since he got sick.

 

I have no idea what could be related if it only happens in overdrive. I'm mostly retarded when it comes to automatics. My friend had a problem with a jeep grand cheerokee doing the same thing. I guess he ran it down a mountain pass in 2nd gear and it was never the same. lol. In overdrive with the torque converter locked it bucked and grabbed, torque converter didn't seem to want to stay locked...

But if it has really been sitting so much I would he changing a few things anyway. Related or not, fuel filter could easily be bad. Sitting so long allows condensation to form in the tank and pool at the bottom. It's best to keep fuel tanks full to keep that from happening.
What's the ATF level look like? Any idea when it was flushed last?

 

Humor me and try this. Drive on the highway, flat ground or downhill with the truck in overdrive. Keep your foot on the gas to maintain speed and lightly keep pressure on the brakes. The torque converter shouldn't stay locked when you're on the brakes. See if it still bucks in overdrive without the torque converter locked.

 

I live on a hill and I have to go down one and up another to go out and about. When I started going up the next hill is when it started until it downshifted.

 

My buddy has the same year truck, doing the same thing. From what he knows so far, it's the TC. Same exact thing my Ranger has been doing. No CEL, just a lot of frustration.

 

a guy at work and my Buick are doing the same thing. Its because a spark plug wire is melted to the exhaust lol. Exact same thing you just described.