When accelerating from around 40-50, or when going up a hill, the transmission will go back and fourth between gears very rapidly, like it can't decide which gear to go in. It goes back and fourth from 1750 rpms to 2000 rpms very rapidly. Any idea as to what this could be?

 

try the easy things first. make sure your tps is adjusted correctly and working

 

Dodge diesel maintenance tips
here is a link on how to adjust the tps

 

trans governor pressure sensor controls shift sensor my be bad or need filter change.need a scan tool to check governor pressure voltage if voltage jumps back prob and fourth probably need to be changed

 

Thanks for the info guys! I'm going to go ahead and start by checking the tps, but I wont be able to service the tranny untill this weekend. Is it safe to go ahead and adjust the front band now, and then adjust the rear band this weekend when I have the pan off? Or do I need to wait and adjust them both at the same time?

 

You can adjust the bands independently of each other. They don't care...

Adjust the TPS also. Might have to hog out the holes a bit to get it up to 1.2 -- 1.4 volts on the center pin at idle. That should help the shift points and also move the spot where the pot inside the TPS is slightly worn to another place where it doesn't bother you so much.