A couple weeks ago I tried to change the plugs. Got the first 2 out on the drivers side, no prob. the back 2 couldn't get to move. It started rain so I put the cop's on the first 2 and just put new cop's on the back ones since I pulled the old ones off. I called the shop up the road and took it to them the next weekend.
Bottom Line- Plugs and COP's DONE! Truck runs muck better, no jerking, slipping or shuttering.

I have a 2006 F150 5.4 with 189,00 on it and had the same bumping/jerking between 45-60 mostly when cruising and trying to accelerate some. I had the fluid and screen changed and it helped a lot but still did it less. The other day I was accelerating onto the highway and it went out on me and the motor revved up to @6000 rpm and I pulled over. Only uses 1st and 2nd now, will not go into drive at all and if in OD, at 25 mph it goes right out again. Leaving it in D at least I can move it. Previous shop told me that I had no screen in tranny and just flushed the fluid. not sure if that contributed to it. My plugs were changed before @100,00 as I did have "popping" noises before I changed them. There were no codes from the engine recently so it is a pretty common problem it seems on these trucks. Truck has been great otherwise for 9 1/2 years now.

There is an issue with these where if the vehicle bucks at the right time or too severely that it can break the intermediate stub shaft. This will cause no 3rd or overdrive. Or, the direct clutch could be toast and that will cause the same issues.

D

Slipping in OD
 

Hi, thank you for the information. It does move in 1/2 with the OD off at least and I got it off the highway and home.

My 2006 (110,000 miles) feels like it misfires, and I am able to replicate it every single time... 1250RPM; 45MPH; slight incline

Have not had the plugs replaced, but will be doing that immediately!

Thanks for the information! I was terrified that this was a transmission issue.