Recently, when I'm driving my automatic 3.0l V6 Ford ranger does not want to go past around 50mph, it shifts up to it find but after that it will not shift, rpms just drop with the speed until it goes back to the gear it was in and revs back up and repeats. No check engine light is on, I think it's the overdrive gear I'm not sure, anyone know what's going on?

 

Should go well passed 50 in 3rd or 4th gear

What year Ranger?

1991 thru 2008 had 3.0l Vulcan engine

Could be partially clogged exhaust
Limited fuel pressure, dirty fuel filter
Limited air flow, dirty air cleaner
None of these will set a code

 

It's a 2001 Ford ranger, it should go way over 50 but it seems like it doesn't want to shift into the next gear at that point