Traveling either at neighborhood or highway speeds, the tranny gives a bucking sensation, hesitaion, every few seconds you feel it jerk.
Is this something to be fixed by a fluid change or is there a sensor that would cause this?

l am guessing it is the overdrive, which is kicking in & out. Would u happen to have overdrive on the ON position? Or D4 that is ?

l resolved it once by a sensor which was easy to replace.

Also, Ford states on it is manuals, that overdrive should be triggered only when driving in speeds such as highways. Unfortunately I've seen alot of tranmission failures because the people leave it on over-drive, & the transmission is doing double the work because it is shifting so often during city traffic.

Hope this helps.

take it to AAMCO.