My 2000 Dodge Ram 2500 automatic transmission hangs up in first gear. If I run the truck to 20 mph and 2000 rpm and then back off the throttle, it shifts to second, then shifts normally from there. This happens every time I take off. If I don't back off the throttle, or drop the rpm's before I reach 20 mph, it doesn't shift out of first. Any thoughts?

 

Probablly need to do trans servcie to check condition of fluid and see if gremlins are lying in pan. If no gremlins, then need to replace gov. presuure solenoid and pressure transducer. Sounds like one has bit the dust and not worth figuring which, Just replace both.
Oh, yes. If excessive metal and or clutch material in pan you are due a o'haul.
Examaple, the magnet in pan looks like and is the size of a Cholocate Krispy Kreem donut.

 

You might also need to adjust the bands when you do that service and pressure solenoid & pressure transducer replacement. BUt as stated, don't be surprised that you're in need of a complete overhaul. Mine was doing the same thing. I replaced all of the above mentionewd stuff, and still.......I replaced the tranny all together.

 

It sounds like the speed sensor on the transmission, this will cause the no - shift out of first gear. Cheap part to replace and can usually be found your local parts place. Thanks Steve B.

 

I checked the fluid and filter. Both clean. There is no evidence of clutches or metal in the fluid or pan magnet. I don't have much experience with the newer electronic transmissions. Can anyone tell me where the governor pressure solenoid and pressure transducer are located? Also, where is the back-up light switch located? Recently my truck has become plagued with sensor failures, one after another. The truck has 122,226 miles on it. Is this about the time all the sensors start to die?

 

Output shaft rpm sensor - Left side of OD unit. Two wire connector.
Gov solenoid on VB sticks straight down and transducer sticking out sidways and attached by same plate.
Backup light switch with three wire pull off connector nestled between cooler lines left side of main case.

 

I replaced the filter, governor pressure solenoid, governor pressure transducer, and the output speed sensor. No change. Is there anything more I can do before I have to change the transmission?

 

This looks somewhat familiar. I had this with my 99' several years ago. It would stick in first gear forever then jump into second or third. Turns out a piece called a "band anchor" broke off. It was about the size of a postage stamp with a round ball shape cut into one end of it. The piece was about 7 bucks at a tranny shop. The guy at the tranny shop said he's only seen a handfull brake and they were all on diesel's. You have to take the pan off and drop the valve body to get to where the anchor is. (I believe dodge builds these tranny's in space where there is zero gravity because I had to balance a big spring and a plastic ball or float of somekind on top of the valve body then stuff it back up inside the tranny without it falling out) Sorry for the long winded answer, im not good at explaining things, but i would check that before buying a new tranny.

 

If you can acheive all gears through pedal movement the tranny is still intact. The problem would still be with the electrical components. It must be wiring to one of the three pieces mentioned and replaced earlier. Suggest going to dealer and have them run diagnostic with scan tool. Output shaft rpm sensor, and governeor pressure solenoid are still most likely circuits.
Don't let someone pull tranny at this time. By your description the tranny clutches are working.