Aisin transmission TEMPS?

[Brutal_HO]

My 2022 Ram 3500 SRW with the Aisin hit 217 F today while pulling heavy up a steep dirt road. It typically runs between 163 and 173.

Was it in 2nd gear or higher the whole time?

If the TC is not locked, the temps are going to go up. The transmission cooler is also affected by higher coolant temps.

 

[bigbendrecycle]

Was it in 2nd gear or higher the whole time?

If the TC is not locked, the temps are going to go up. The transmission cooler is also affected by higher coolant temps.

I'm pretty sure it was in 2nd. It was also in 4wd. It sounded like the cooling fan was tacked out! Next time on approach I'll manually keep it in second. The coolant was running in low 200s along with the oil. It's the worst conditions for the tranny, slow steep grade and loaded down heavy.

 

[John Jensen]

Two or three times a year I tow my 9800lb pull trailer on a 120 mile trip to our dry desert camping spot. The return trip home has an 8 mile 6% grade coming out of the desert into mountains gets to 8% in parts. I put the truck on cruise @ 65 mph and in tow haul. The truck ran consistently in 6th and 5th gear up the grade. The Tranny ran at 163 degrees except topping the grade it hit 167 - amazing! Topping the grade the coolant hit 222 and oil 228 for about 1/8 mile, then quickly down to normals. EGT1 peaked @ 924 degrees.
The truck stayed at 65mph and pulled like the trailer wasn't there, with power to spare.

I am Calibrated tuned. The above data was while running their heavy tow tune (+40hp).

 

[bigbendrecycle]

Two or three times a year I tow my 9800lb pull trailer on a 120 mile trip to our dry desert camping spot. The return trip home has an 8 mile 6% grade coming out of the desert into mountains gets to 8% in parts. I put the truck on cruise @ 65 mph and in tow haul. The truck ran consistently in 6th and 5th gear up the grade. The Tranny ran at 163 degrees except topping the grade it hit 167 - amazing! Topping the grade the coolant hit 222 and oil 228 for about 1/8 mile, then quickly down to normals. EGT1 peaked @ 924 degrees.
The truck stayed at 65mph and pulled like the trailer wasn't there, with power to spare.

I am Calibrated tuned. The above data was while running their heavy tow tune (+40hp).

My temps typically range 168-173, and seem to be dependent on outside temps. This hill is especially hard on rigs, I had it in 4wd the whole time towing around 19k GN with equipment. I'm going to be hauling steers tomorrow around ranches and will see what it does.

 

[John Jensen]

My temps typically range 168-173, and seem to be dependent on outside temps. This hill is especially hard on rigs, I had it in 4wd the whole time towing around 19k GN with equipment. I'm going to be hauling steers tomorrow around ranches and will see what it does.

The outside temp in my example was in the 80s coming out of the desert and up the grade. You are probably hauling more weight than me, I think your temps are OK

 

[Brutal_HO]

I'm pretty sure it was in 2nd. It was also in 4wd. It sounded like the cooling fan was tacked out! Next time on approach I'll manually keep it in second. The coolant was running in low 200s along with the oil. It's the worst conditions for the tranny, slow steep grade and loaded down heavy.

My temps typically range 168-173, and seem to be dependent on outside temps. This hill is especially hard on rigs, I had it in 4wd the whole time towing around 19k GN with equipment. I'm going to be hauling steers tomorrow around ranches and will see what it does.

At that slow speed up a steep grade, 220F max is not unexpected for a load that big.

You can't prevent a downshift, but if it's shuttling between 2nd and 3rd, it might be best to limit it to 2nd and prevent those shifts that are creating more heat. If you have to go slower, or run in 1st I'd consider using 4-lo or also consider getting a 2-Lo lockout box. The only downside is 4-Lo (or 2-Lo fake) turns off the EB.

With the loads you're running, you may want to look into an aftermarket thermal bypass valve to replace the stocker if you're in a consistently warm climate.

Not sure if this Mishimoto fits 19+ but it has the option to run a bypass or thermostat.

Thermal Bypass Valve Kit, fits Dodge Ram 6.7L Cummins 2013–2018

The transmission is the backbone of your 2013–2018 Dodge Ram 6.7L Cummins. It’s responsible for transmitting up to 930 lb-ft of torque from the engine to the wheels. That much power generates a lot of heat and if that heat isn’t dissipated, it can destroy

www.mishimoto.com