Transmission Won't Shift
 

Long time reader, first time poster.... Returned from Florida last night and truck sat for about a week. Ran perfectly fine right before I had left. Got in the truck and noticed it was not shifting at all. I took it easy and was only able to get it to shift going downhill. Otherwise, the truck will not shift at all. I recently replaced the fuel filter. There was nothing on the driveway indicating a leak other than a puddle of what appeared to be water near the front driver side. Any assistance would be big time appreciated. This forum has been a big help to me. I am thinking possibly governor pressure or some other type of sensor??

2004.5 Ram 3500 Laramie Cummins, Black w/ silver, Long Bed, SRW, 4x4, 2" spacer, 285/75/17 nitto terra grappler AT, 5" tip, limo tint, 150k miles, motor stock

OK, first Q: any codes? Light for check engine.
Second Q: Does it shift if you lift or just going downhill? I assume it shifted at least a little since you were able to drive it some.
Is the O.D. button on or off? when it does this?
Does it have good reverse? Firm engagement? or slushy.?
The water was probably from a topside drip, or A/C unit evap. (mine does that too)
Any chance you could get a DTC reader on it or can you turn on the ign 3 times without starting it and see what code is displayed in the odometer readout?

Have you checked the fluid level? Probably not it, but start with the cheap stuff.

No codes being thrown. Ran a diagnostic check and did the key cycle and nothing. Fluid level is full, needs to be changed, but still full. The truck engages perfect in reverse. I pushed the tow/haul button with still no effect. I have had no previous issues with the transmission. It has always ran smooth and had firm shifts. It is really odd how it sat for a week and now its not running right at all. Auto transmission by the way. Any help/ideas would be much appreciated. I even called the local Cummins dealer and they won't touch it because it's not a motor issue and the dealership wants 100 bucks just for the diagnostics test. Thank you to all/anyone for your help!

I would start with the solenoid. its about a hundred bucks but changes pretty easy if you are at all mechanically inclined...... my .02

Try the governor pressure solenoid and transducer. That's what it sounds like as everyone else has stated.

Update ** Thanks everyone for the input. Got the truck out again tonight. It is finally shifting, however nothing what it used to. It's still shifting real high, however I am able to get it to shift and its not stuck at 20 mph and just revving rpms. I got it out on the freeway and it seems like I can't get it to shift into OD. I haven't fixed anything yet on it just drove it around a bit to warm it up. I know in the owners manual it states that if truck hasn't been driven in a few days shifts may appear sluggish b/c water drains from the torque converter to the transmission. I am going to look into changing the governor solenoid and transducer tomorrow. Anyone have a part number or know of a good place to purchase either of these parts? or possibly have them from a stock tranny? Also any input on changing vs. flushing trans fluid and adjusting the bands??
Also, is there any info I could look up to reference or manuals recommended for these repairs.... ie Haynes Manual etc...

i just changes those in my 04 today. ramsey motor. (my local dodge shop) was the cheapest

what were you experiencing with yours? and did it help by replacing?

I found them the cheapest at the dealer as well.

had same issue with my 04 after sitting for a month had dealership look at it nothing replaced solenoid and sensor nothing then bang it hit me she was starving for fuel new filter and perfect , i know u stated u changed it recently but worth a try , it did not seem like a fuel problem at all but it fixed it

update** drove it again this morning. it was somewhat shifting last night. its back again to not wanting to shift at all. i think i am going to have the governor solenoid replaced and transmission fluid changed today. any thoughts on transducer and whether or not i should consider replacing this as well?

Alot of people will say if your doing one to do the other. They run hand in hand. When i did mine i only did the solenoid. I dont know if your tranny is set up the same as mine, but i had mine hanging in second and it ended up being the front band. Might see about having your band adjusted as well..... Im sure any knowledgeable mechanic would be able to tell in a heart beat if it is the band.

Sounds good. Thanks to all for the help and suggestions. Dropped the truck off to mechanic today to change fluid and solenoid. If anyone else has any suggestions please let me know. I am stressing out big time about it and just hoping that this will fix it. I love the truck and it's my baby. Thanks again and will keep all posted.

UPDATE***** Replaced the governor solenoid, sensor, transmission fluid and transmission filter. $350 later , Truck rans like brand new again. Thanks everyone for your help it is greatly appreciated.... could it be time for a smarty jr and some gauges now... haha...