I hope someone here is smarter than me and can point me in the right direction. I have 1999 1500 with the 5.9 and auto trans. Last spring i was plowing snow on my farm, put it in reverse and there was pretty much nothing.... I figured i must have burned something up in the trans, i know plowing is the easiest work on a trans. If i gave it a lot of gas it would just move a little. I dropped the pan and looked around with nothing looking immediately bad. My guess was i burned up the rear band. Parked it until this fall, found a donor truck for cheap and went about doing a full swap. Initially I just moved over the engine and trans, splitting it at the overdrive. got everything put back together only to find... still no reverse went ahead and moved the overdrive and T-case from the donor truck as well in case they were the issue but the problem is still the same. ON the flat in the shop, it has just enough oompf to get it rolling back. but any resistance or going uphill it wont do anything. I dropped the pan, torqued the rear band, new filter and fluid. Took it out for a drive and got it warmed up, it goes through all the forward gears and OD. If i hit the OD Off button it revs up so im assuming the OD is going in and out as desired. at this point im just absolutely flabergasted. I dont even know where to look next. Ive been browsing the diagnostic chart linked below but im not even sure what to try.

Either something external to the transmission is causing the issue or I got really unlucky and reverse magically broke on the donor trans while i was swapping. Hopefully i gave enough info that someone has an idea, i can fill in any gaps as much as i can if there are questions

https://mopar1973man.com/cummins/art...7re-48re-r352/

 

Try disconnecting the 8 pin connector on the trans, and see if anything changes. Keep in mind, it won't have ANY automatic function, and you won't get TCC, or O/D either.

 

If it does move slightly in reverse i would suspect worn(or misadjusted) band or the reverse servo has an issue. Might want to check the shift linkage is adjusted correctly.

 

so unplug it then start it and see if it goes into reverse?

 

We tried unhooking the shifter and manually clicking the transmission into R with the same results. what kind of issues/tests can i look for with the reverse servo? I'm not super transmission savvy but willing to learn

 

Yes
Download the FSM in the FAQ section. You will need a pressure gauge and it will tell you what to do and what to look for.

 

to anyone curious, after reading through the shop manual, i came to the conclusion that when we swapped the OD units we must have had something not quite right with the thrust bearing/piston/whatever. Pulled it apart tonight and sure enough that thrust bearing had failed... full detonation. got it all cleaned up before my *** was froze off laying on the cold cement. will get it put back together tomorrow or the next night and hopefully be backing all over the place like a mad man