So full disclosure... I have not towed anything heavy yet, nor driven with the plow in or plowed yet.

That said, getting a baseline for "normal" I was a bit alarmed to to regularly see transmission temps above 200°. My 6R140 from my '17 almost never got above 185, unless I was plowing a lot, and even then 205°F was about the max. After 20 minutes of highway driving (45-65mph) unloaded my 22 was averaging 205°F. I understand the cooling on these is through the oil/coolant, but for transmission temps it still seems high for an unloaded, cool temps highway drive.

Is this just because the diesel runs hotter, or do all the 10Rs run hot like that? I'm curious how hot it'll get this winter.

 

The newer transmissions like to run hotter. My transmission temperature will get into to the 230's when towing up the mountain passes here in Colorado.

 

I’ve had both and 10R’s do run hotter than 6R’s. I never saw my 6R over 201 unloaded. My 10R will run 212 unloaded.

 

That's normal to see. From a previous post..Operating temps ranging between 200-221 for drive. Ambient temp 92-101f, 75-80 mph most the trip.

https://www.ford-trucks.com/forums/1...l#post20362891

 

10r140 is designed to run at higher temps than older transmissions, it is designed to handle it, the fluid is designed for those temps.
The cooler is thermostatically controlled by the ecm.
The ecm monitors all operating parameters and if there is any issue it will let you know.
I have only looked at the trans temp on mine once when it was new and have not checked it since, and I tow heavy often, no worries at all.
Don't borrow trouble!

 

my 2021 250 ran just under 200f at 78 speeds in 95f OAT

 

My 2022 F450 runs 205 - 209 unloaded . . . was worried also but seems to be normal

 

Best I can recall, my 22 runs about 190-200 unloaded.

 

around 210 unloaded at normal temps. Upwards of 220 to 230 when heavy towing.

Never gets more than that. the cooling strategy is pretty agressive when oil (engine oil) temps get around 225F and that tends to cool everything down even though the trans oil cooler is in front of the trans.

 

After seeing my temp at 218 not towing in the flat land of Kansas, I was pretty concerned about towing. My ‘19 GMC weighs 14K with a Knapheide service body and with a 32 foot enclosed trailer tied off to it, it might occasionally get to 200. What’s Fords logic behind high operating temps?

 

It's gotta make 60,000 miles.

 

From Ford
"Transmission fluid Transmission fluid should be checked with the vehicle on a level surface and at normal operating temperature. (Normal operating temperature 90°C (195°F) to 101°C (215°F))."

 

Before I left Ford Automatic Transmission Engineering in 2007 there was a lot of discussion about raising the transmission operating temperatures.

The reason to raise them is fuel economy. The transmission is more efficient (it wastes less torque) at higher temperatures. Fuel economy is one of the highest drivers at Ford. The materials were upgraded so that the life of the transmission wasn't affected, the customer just gets better fuel economy.