In my 1996 3500 the Cummins is great but the weak link in the puzzle is the tranny. It is the four speed auto with overdrive and on the back roads it wants to hold second gear and third seems very elusive. Once in OD it pulls great but the thing seems to either want to scream in second or go to third for just a minute then back again. Is there really any helping this old Mopar tranny? I have been told that shift kits don't generally help in this case but I guess I need more input from people that actually pull loads.

 

While I can't answer you 100% in relation to what you are dealing with, I will tell you what I expereinced. My 94 was hunting in and out of O/D, as well as dragging it out until shifting. My transmission is fairly new, so I didn't suspect an issue there. I replaced my TPS, which made a world of difference, on both accounts. Before you pony up for a TPS ($126 at Autozone), you should make sure that is your issue- I don't want to tell you to spend money that isn't necessary. If I were you, I would take the TPS off, and check it. On mine, I could see very appreciable wear on the inside socket, where the throttle shaft goes into it. I think that the PCM wasn't getting true input from the TPS, because the throttle could move without sending input to the PCM. Now, not only does mine shift into OD when it is supposed to, it isn't hunting in 2 or 3, either. Replacing the Throttle Position Sensor took care of my issues. I have put about 500 miles on the truck since replacing it, and it hasn't misbehaved once.

 

It sounds like you may have a sticking solenoid or something similar in the valve body. You need to call a good tranny guy that can give you some advice.

Call Goerend and talk to Dave or Les(i think) there. www.goerend.com

They will be able to point you in the right direction with fixing your problem, and wont try to sell you anything you dont need.

I dont believe you have a TPS issue. A bad TPS usually only causes problems with lockup, and the 3rd to 4th shift.

Eric