What's new
Ram Heavy Duty Forum

Register a free account today to become a member! Once signed in, you'll be able to participate on this site by adding your own topics and posts, as well as connect with other members through your own private inbox!

Transmission issue

cnewstead

New Member
Messages
9
Reaction score
2
Points
3
I am a new owner (first time diesel) to a 2020 ram 2500 tradesman. 147k miles, deleted and tuned, 4in lift with 35s.

Last night I was driving normal on the highway when all of a sudden a warning light comes up saying “Trans to Hot”. I checked the trans temp and it was maxed out at 275*. I quickly got off the highway and as I was doing this the temps started to drop back to normal. I was back in the 175-185 range. I did not have any weird shifting, smells or sounds.

Next morning I checked the fluids and I was very low (almost nothing). I topped it off. I decided to check the thermal bypass unit to see if it was clogged. It all looked normal. I then topped off more fluid since I lost a lot from checking the unit.

After driving for about 15mins the shifting was off, and I got a cel light. The truck did not like first gear. Ran the codes and I got a p2509 and p0731. Checked trans fluid and it was bone dry. Topped it off again to normal level. Erased the codes and drove about 2-3mins and everything seems fine. Checked fluid again and it was showing it was good.

Anyone have any advice? I’m new to diesels and want to make sure I’m doing everything I should. I’m thinking for buying a new thermal bypass valve. The one that’s currently on the truck is unbranded, so idk if that’s gone bad. I also was thinking it could be the trans temp sensor?
 
Where was all the fluid going? Any sign of it undercoating the bottom of your truck?
 
Just to verify, how are you checking it?
 
Transmission dip stick

How, not where…

There is a fully detailed procedure in the owners manual for how to check the transmission fluid, I suggest you start there.

Short story is that the trans needs to be running to have fluid in the proper places. There are provisions to check it both hot and cold, but hot is preferred.
 
cnewstead:
Did you get this figured out and straightened out? With no fluid on the underside of the truck or ground and the coolant not being a bright brilliant pink is the transmission over full?
 
cnewstead:
Did you get this figured out and straightened out? With no fluid on the underside of the truck or ground and the coolant not being a bright brilliant pink is the transmission over full?
Turns out truck was extremely low in transmission fluid. I also added an ATS Thermal Bypass and everything seems to be perfect now. Driven a decent amount and temps stay cool. Shifts buttery smooth
 
Turns out truck was extremely low in transmission fluid. I also added an ATS Thermal Bypass and everything seems to be perfect now. Driven a decent amount and temps stay cool. Shifts buttery smooth
Thats awesome!! that it worked out and all is well.
 
Thanks! I was so nervous thinking I was going to need a new transmission. Only had the truck for 3 weeks lol
 
Back
Top