I just bought a 99 f150 it has 257000 miles on the truck, and a motor and transfer case from an '01 with 215000 miles. I'm not sure about the maintenance on the truck but when I'm on the highway the truck randomly stutters. I was thinking it was coming from the tranny because the tranny was overfilled by almost a quart but really not sure.

 

My 98 F250 was overfilled a bit and I didn't think anything of it. It was a rebuild about two years old. It blew up with us out in the desert and cost about $2000. last year.
I'm no expert on transmissions but there must be a reason instructions say do not overfill.
You will probably get some good advice on this post, which may include taking the truck in to have the transmission examined and serviced.
Good luck to you.

 

Could be tranny. that sounds to me like it's more likely a bad coil

 

Misfires CAN feel like a slipping transmission.

What engine is in the truck?

Is the SES on?

 

It has the 5.4 no check engine light. Its ran fine for the last 60 miles.

 

very often a bad coil will not throw a CEL. Generally you will feel a studder when in OD and giving gas. Like going up a hill on the highway. The low rpms and larger amounts of fuel require a stronger spark, so a weak spark will cause a misfire. The TC should be locked when you are on the highway, so im not sure how it would studder. It would almost have to be ignition related.

 

Looks like ill be changing plugs soon and cops.

 

If your tranny is over filled it can cause the fluid to foam. This usually won't cause a slip, but it can cause a shudder at low speeds. I see this more when cruising around town at about 30 mph under no load. It will feel more like a rotational vibration. Once the fluid is brought to the proper level and it sits a few hours it should not cause problems.
My expedition was doing that for a few weeks. I thought the same, it was slipping in the tranny. It never gave a trouble code, until the coil finally went. Then it gave a code, changed the coil and the problem was solved. It typically won't store a trouble code until it detects a repeated misfire. What is probably happening to you is just 1 misfire every once in a while. Probably more under load at slow steady highway speeds? My expedition is doing it again, but mostly when pulling my camper at a steady pace slow speed like 40 to 50mph. Instead of spending the money to replace all coils I will wait until it gets worse and sends a code.