Trans temp too high?

[BIG RED BUBBA]

i have been towing my trailer with my four wheeler on it and over hills and mountains that are pretty steep for about 15 miles on and off. my trans temp is at 190 when on smaller hills but i have seen it jump up to 240 when it was 107 F out and i was near the top of a 12 mile grade. my temp warning went on at 225. my engine and engine coolant were also at 225 when my tranny was up there, could this be a flow issue? the four wheeler and trailer combined are about 10k lbs.

[BIG RED BUBBA]

unloaded my truck runs at
ECT: 194
EOT: 195
TFT: 168-170

loaded on the flat it runs at
ECT: 199
EOT:201
TFT:180

and my exhaust temp never gets too high, never above 1200 F

i should say as well that when my temps spike through the hills they go right back down until the next hill.

[dereku]

I dont know 6.4s at all but it seems odd that the coolant and trans were identical temps.

[BIG RED BUBBA]

the coolant was a little bit below the trans

[ThirdCoastStroker]

something must be going on in there, the only time i have ever seen my tranny get over 215* is when i was towing a gooseneck with a 19k pound tractor on some back roads and i couldnt go over 35 mph because of all of the curves and it was about 130* ambient air temp

[BIG RED BUBBA]

ya that is what i am worried about, these hills that i were on were all windy and 35 mph roads. but when i was driving today i noticed that my truck got up to 201 eot when going up probably a pretty steep hill while sticking it at the speed limit of 30mph and not letting it down shift.
i do live in the hills somewhat, on the peninsula of the san francisco area we have some pretty big hills but i am worried that it rides so high just trying to get up a hill in town unloaded.
what should it be at when unloaded on a hill?

[RobertS450]

The TC needs to be locked when pulling these hills or the trans will get hot cause the tc is in fluid coupling and making tons of heat. Also with higher rpm the fan will be spinning faster moving more air across the coolers. I know lots of guys want low rpm but these are not cummins and need rpms to make good power and torque. So if you are pulling loads under about 1800 let it downshift and get the revs up.

[BIG RED BUBBA]

ok thanks for the advice, i will try that next time i get out in the truck

when i was towing on the way back i tried shifting into manuel third every time i would approach a hill and that kept the trans temps below 220 the entire time so i was happy, it was definitely the higher rpms keeping it down