Hello all,
Super new here.. IDK where to start. But I need help. I apologize in advance for my lack of Knowledge or correct Terminology or even the heck everything is called. OK so my 2000 Ranger XLT 4.0 wont shift up into 5th. Only sometimes. I take highways all day every day. speed limit is 65 I'll get up to speed and about 30mins or so into my drive(with my foot on the excelerator steady the whole time) my rpms rise from 2100 to 3000 I'll let off the gas allow it to go down then back to the gas. then at a normal 2100 RMS. now sometimes this works sometimes it dont. Most of the time if I'm going down hill and I let off the gas a tish it will shift. Theres times where it just stays in what it seems 4th gear. It's like the OD is not working properly I feel as tho. That OD OFF light flashes on most of the time this happens. I've done nothing well cuz I cant find anything on line that matches my tootsie's (my truck) shananigans.

 

The better thing you might consider is to have the vehicle checked for codes which should provide some direction.

There could be a few reasons for the trans torque converter to keep locking and unlocking.and also for the trans to keep downshifting out of overdrive