F250 shifting issue

I have a 2003 F250 with a 5.4L V8 automatic transmission with 64,000 miles. The truck runs and drives well, but occasionally while driving, it acts like it shifts into a higher gear, slips a bit, then downshifts and runs fine. The duration of this “acting up” is about 1-2sec. It seems to do it when going up a slight grade at cruising speed about 40-50mph. (Not towing when it does it) It doesn’t do it all the time. Any ideas? I’m planning to change the filter and fluid but am doubtful that will help. The fluid color is nice bright pink and does not smell unusual.

How long have you owned this truck? It sounds like the problem is the result of the TCM searching for the “ideal” gear and ranging in and out of OD. Certainly, get the transmission serviced with the proper ATF and scan for codes. Post results.