Tranny overheated

[kfp673]

Hello All,

2018 Ram 2500 6.4L Hemi with 4.10. Heading back from camping today, tow/haul mode on, after a long hill my truck suddenly left "D" and locked itself in 4th gear. I was on the highway doing about 65 so it was not that big of a deal, but I could not make it go back to D, upshift, downshift, nothing. Kept driving 2 miles until the next exit which happened to be mine. Seemed fine until I came to a light in town. It never left 4th. Needless to say it was not pretty trying to start from stop with 10k Lbs trailer in 4th gear. Got it going just to clear the intersection and pulled over where I could. Just as I pulled over a light said "Transmission is too hot". I let it idle for about 5 minutes hoping the trans cooler would cool it. After that 5 minutes the light went off but I was still stuck in 4th. Turned the truck off and re-started and all seemed fine for about 4 miles and then the same thing. I was about 10 miles from home thankfully so I limped home, shutting down and restarting at each light. Almost home the engine light went on. I am in warranty so I'll take it in this week but curious if anyone has seen this issue. Truck pulls the trailer great and never had an issue. It does scream sometimes pulling long hills but never felt like it was struggling. Also strange that when I re-start it shifts fine until it locks in 4th again after 5-10 min. Any thoughts? Thanks!

[dodge_guy]

The pan needs to be dropped to change the solenoids, basically the entire valvebody. So about 5 qts of fluid will be changed out. And yes I've seen those solenoids fail before.

On my vehicles that towed or hauled I changed the trans fluid every 25k miles. Overkill, maybe, but a trans fluid change is cheaper than a trans. Although the new 8 speed fluid is pricey!!!!! The 6 sped still uses ATF+4

[kfp673]

I was not planning on having them change the fluid since it’s only 26k miles, but now you have me thinking. Going to call back in the morning to discuss. And yes it was overheat. I have the larger dash display and it actually says those words “Your Transmission is too hot”. That was on just for a few minutes until I pulled over and it went off. THe regular engine light did go on and stayed on as well but the truck did say the tranny was too hot. I was kind of hoping they had to drop the pan and the service would be included, but they are telling me these solenoids are mounted to the side of the transmission and the pan and tranny do not really need to be touched. Again, I’ll call in the morning to discuss the fluid change.

Thanks again all!

[time2roll]

Was it really an overheat light or a generic transmission fault light?

+1 on changing the fluid sooner than later if it was truly an overheat condition.

[rhagfo]

kfp673 wrote:
Apparently the code the truck provided was a bad solenoid. They come as a pack according to the dealer so they are replacing them all. The overheat likely came from being in 4th gear and starting from a stop so hopefully no major damage was done to the clutch or anything else. I pick it up tomorrow so fingers crossed that fixes the issue. Thanks again all!

If the trans got that hot, did change the fluid?

[kfp673]

Apparently the code the truck provided was a bad solenoid. They come as a pack according to the dealer so they are replacing them all. The overheat likely came from being in 4th gear and starting from a stop so hopefully no major damage was done to the clutch or anything else. I pick it up tomorrow so fingers crossed that fixes the issue. Thanks again all!

[Grit_dog]

C Schomer wrote:
A hemi with a 68rfe??

No

[C_Schomer]

A hemi with a 68rfe??

[CapnCampn]

I've got a 2014 Tradesman trim, and the tranny temp is displayed in the info center in the menu right above fuel economy (I can't remember what it's called)... the one that defaults to showing the tire pressure. So I'm sure it's available and not too deep in a bighorn trim.

My fingers are crossed for you!

CC

[kfp673]

rhagfo wrote:
Kfp673, what is the trim level of your 2018 Ram. On Big Horn on up you should be able to display the engine, trans, oil temps and oil pressure easily.

Big Horn. Going out in a minute to drop it off at the dealer. I'll play more with the dash menus then. I'm sure the truck gods will make everything work perfectly and there will be no problem found 😉

[rhagfo]

Kfp673, what is the trim level of your 2018 Ram. On Big Horn on up you should be able to display the engine, trans, oil temps and oil pressure easily.

[kfp673]

Hello All. Thanks for the replies. Answers a few questions / comments, no I did not check the trans temp as I don’t know how. Was just trying to get the family home and could not find it quickly on the dash. It did read “Transmission is too hot” when the light popped up though.
Addressing another question, it has about 26k miles and about 2 1/2 years old so should be under full warranty. Dropping it off later today. I have not even restarted it since I’ve been home so no idea as of now how it will behave.
Weather was about 75 degrees (Crazy for November in PA) and it was a typically interstate PA hill. No idea the grade but I am not talking about straight up. Probably 2- 3 mile pull where it did downshift for a while as it always does. Was traveling between 65-70 MPH and with the 4:10 I have no problem pulling them and maintaining speed typically. It was as if it had shifted to 3rd for the hill, then when I got to the top it shifted to 4th and the dash showed as if I had manually selected 4th. I held the + button like you would to go back to D. It showed D and then immediately shifts back to 4th as if manually selected. As noted, an engine restart “resets” it until it happens again. The last 2 miles I learned if I set it to 3rd so it never makes 4th I was OK to get home. This was ok because at this point all of my roads were 45mph or less.

Anyway, was just curious if anyone has seen this

[ppine]

People are asking the right questions, except for one.
How much weight are you towing? Burning up a transmission is the most common thing that happens with too much trailer and not enough truck.

[rhagfo]

KD4UPL wrote:
Well, the basics are:
Did you have enough fluid in it?
Do you service your transmission regularly including fluid and filter?
Do you have a transmission temperature gauge? What was it reading?
It could be a computer glitch, could be a trans problem, could be an actual overheat due to outside circumstances.

Well depending on trim level for the instrument cluster the engine and trans temperature should be available on the instrument cluster.

If still under warranty should be somewhat low miles 2018 6.4 with 4.10's, 10,000# should be well within tow ratings.

Differently need a bit more information.

Weather when this happened?

OP states after long hill, how long, and how steep, how fast were you climbing?

Can and did you check trans and engine temp while climbing that hill?

Have you checked the trans fluid level since this happened, and is it correct?

Have you checked the engine coolant level?

Could be just a faulty sensor sending bad data to the management computer, or a slipping trans.

[deltabravo]

How many miles on the truck?

I'm guessing that it doesn't have a trans temp gauge, since the OP never posted what the temperature was and only mentioned a dash light turning on.

[4x4ord]

Is it low on fluid?