I have a 2000 dodge diesel short bed 4wd automatic trans, when driving down the road between 35 and 50 mph the transmition shifts up and down every 3 to 4 seconds i have to either apply more gas or let out to get it to stop doing it, i have a 113k on the truck and have changed the fluid and filter 4 times since new the last time the fluid was clean and bright not burnt at all. does anyone have any suggestions on what could be causing this ?

thanks Dan

 

Check your ground wires. Also if you do a search you can probably find a lot of info on this problem.
I had the same problem and had to buy a Happi box. It has worked great for years and the problem has never returned. www.happibox.com

 

AllanP is right, check the grounds. Mine did that and I added a ground wire from the battery to the apps. Works like a charm now.

 

Hey badme can you give me a little more on adding a ground wire from the battery to the apps? What size wire did you use, etc?

 

Try cleaning the battery terminals and cables to ensure a good connection as a preliminary step.

 

I just went to my wire rack and picked a roll of black that looked good at that moment. The guage is not that important. 10,12,14 what ever you got will work.
Then remove one of the bolts that hold the apps on. They are the 13mm ones.
Run the ground wire from the bolt to the battery ground terminal. The idea is to remove line noise, you can buy a noise filter or I have seen threads to reroute the apps wires but this is fast, cheap, and easy.

 

Thanks I'll try it. I already have cleaned the battery terminals and cables.