Sometimes can't get out of gear I'm in without really jamming on the shifter. Mostly happens between first and reverse. Also shifter will occasionally drop into the neutral position while driving in od-and won't shift into a lower gear until I jam the shifter back to od, then I can go down in gears. Is this a tranny or maybe a clutch issue?

 

It sounds like the shifter part of the trans needs some attention.

 

It would really help to know WHICH transmission the truck has. Click this & read the whole caption: