Delavan

Thanks again all!
My truck only has 32K miles on it. I will indeed consider changing the tranny oil at 70k miles.

Delavan

***Update***
I did some uphill towing goign camping up the hills and through mountain passes. When the speed is 55-60 Mph, the transmission temps are usually at 197-204F. But sometimes, when I need to reach a elevated camp site, I have to climb a 7-8 deg grade at low speed. Transmission in 2nd or even 1st gear. Then I back the trailer in a spot, which is another ocassion where the transmission's temp raises. Temp reaches 228F. This is with the digital reading from the productivity screen. Meanwhile, the temperature gauge needle is not even reaching the half-way mark....does it means that the needle gauge is very innacurate, or the 228F temp is not so bad?

Im getting from this topic that I shall not reach 228F, cause it will ruin the tranny fluid....so dashboard gauge is crap inacurate?

13EBF150

Delaven, sounds like your truck is running normal. We tow 90% of the time in the the Southern Rockies of Southwestern Colorado, Elevations of up to 10,000 ft. with grades of 6-8%. We see tranny temps up to about 215 to 218. ECT's get up there at times, 230 to 235. Temps don't stay there to long. I try to keep speeds around 45-55 mph and as low a boost as possible running in 3rd & 4th gear if I can. I'm not concerned with our temps. Truck has a smidge over 40,000 miles on it.