Mine did the same thing,.. I've got a plow on it and was plowing for over 10 hrs
two nights before. I thought I had toasted the trans! (Even though Over-drive is off when I
plow). As the day wore on, (About 20 miles) it shifted just fine in and out of Over-drive.
It's a temp-thing.

 

The factory manual that came with my truck stated that the transmission would not shift into overdrive or lock the torque converter until the transmission reached a certain temp. My transmission however will shift into overdrive and lock the torque converter when the outside temp is as low as -5* F (thats the coldest I've driven it so far). So ironically while your tranny is operating the way it is supposed to, mine is not.

 

Dodge built this into the auto tranny, so thatwhen thefluids are really cold it wont hurt the O.D. Mine does the same thing and it really makes me mad when I have to use drive for 45 minutes. Just watch the gas needle go down. You can have a bypass put in to jump the cold weather sensor and let the tranny shift into O.D. But if you have any problems with your tranny related to cold weather good luck.

 

Both my dakota and ram transmissions wont shift into overdrive after it gets below zero nomatter how far i drive. Alsoif i dont let the truck warm up when its cold out (0 to 20 degrees or so) it wont shift into overdrive until the tranny has warmed up to 50 degrees or whatever the factory set point is to shift into OD.

 

Yeah, I just let it warm up today for a few minute before I left for work. It still didn't go in to OD till after I stopped to get gas about 10 miles from the house. I'm sure it wouldn't take as long to warm up the trans if I had a lot of stop and go driving to work. But I drive over 75 miles one way and it's all Interstate, and the drive to the interstate is only a mile and a half from my drive way.

Glad to hear that it's just running the way it's suppose to.

 

i have to ask . do you have a trans cooler? could be the answer for the hunred mile warm-up.

 

Yeah, I had a trans cooler put on when I had the Jasper Transmission put in. The Jasper people recommended a trans cooler with larger line running from the trans to the cooler, so I had them add that to the install. I think they're half inch steel braided lines that run to the cooler. I was thinking the same thing about the cooler too.

 

Mine used to do that very bad, It was rebuilt with the past owner, a cooler was installed and the radiator cooler was bypassed... It got much better when I flushed the radiator cooler and reconnected it into the circuit. Still does that but it takes less now. Maybe someone did the same with yours, that thermostatic valve in the cooler was the reason it needed the rebuilt, high temp light on and transmission is gone.

 

It's allPCM programing the locks out OD. It's done on purpose because in cold weather the fluid can gel and starve the overdrive. I've seen it and the damage can be extreme. You can disable the overdrive lockout with the factory scan tool (DRB III) but you are supposed to install an additional cooler bypass kit to prevent starvation. I don't know if any aftermarket tool can disable the lock out.