Automatic shifting issues with 2001 7.3L F250

cannesdo wrote:
Just today it starting staying in (I think) 3rd and reving up rather than moving onto fourth. (Didn't rev like it was in neutral. It was still accelerating but the RPMS were wound way up) If I accelerated really carefully I could get it to shift all the way up without "sticking" but if I was hitting the gas hard at all it (or even normally) it would stay in 3rd and rev. If I take my foot of the gas it will usually shift up to fourth, but not always.

It started when I was accelerating pretty quickly which I don't normally do -- not crazy fast, just quite a bit faster than usual. Last week I towed my 36' foot fifth-wheel for two days but I've been driving it for five days now without any issues. Drove down the mtn today from Woodland Park, CO (just the truck) to Colorado Springs (from a cool place to hot place if that's relevant) and it started when I was down there. Also dropped 2000 ft. No idea what could affect this so I'm throwing everything out there.

I do not understand the temps you gave.....128 for the engine and 112 for the tranny. Normally should be...around 195 for the motor and 160-180 or so for the trans.

I was really concerned about it climbing up to Woodland Park last week as it was a hot day. I waited down below and cooled it off before starting the climb. Engine temp maxed out at 128 and transmission temp was about 112. I usually don't let it go any higher than that but had gone that high many times before so I thought it was probably ok for the short climb (15 min. Worst of it was only about 7 min. Took the climb like a champ.

Had the truck since '07, put 40K miles on it since then, 130K total... not much towing. I stay in each place for quite a while.

Thanks for any input.

The truck is chipped (Edge Evolution) No warning lights came on today. Should I disconnect the chip and see if that resolves it? I checked all the fluids before leaving. I'll check them again in the morning.