I've got a 99 6 speed powerstroke 2wd with 227k miles and if you try and use 4th gear or you may call it 5th if you use LOW it will get stuck and you pull it out into neutral it'll still pull like its in 4th. You can put it in any other gear but I won't let out on the clutch cause it would problay really brake something then. I really need to get this fixed today please if anyone can tell me what's rong with it.

 

Pstroke1999, I can't be of much help but I remember a thread somewhere about a roll pin backing out of the shifter linkage where it goes into the top of the transmission. If that pin backed out I could see where you would not be able to change any gears. The plate that holds the shifter handle in has 6-8 allen head screws and the pin can be seen once it is removed. Good luck. Oh...if the pin is missing that means it is in your transmission somewhere. Maybe a magnet through the drain hole??

 

Has any inspection been done on the trans? remember also the plastic pedal bushing wears out and will cause a disengage scenari. Its a little part that is an easy fix and cures a hanging up shift fork symptom