Transmission Fluid Temp

[RUSSELL5000]

Took a nice trip to West Virginia recently with the truck and trailer in signature; in West Virginia there are some 6% and 7% grades on the interstate, a number of these on the route to where we were camping, and an assortment of 9% grades on the route to camping (the longest 9% grade was three miles).

I was watching the transmission fluid temperature (EVIC) on the trip back and forth. The outside temperature was in the high 70s on the trip out; was in the high 80s on the return trip. Fluid temperature was very consistent between 150F to 155F on trip out, but between 168F to 173F on return trip. The difference in fluid temperatures was greater than the difference in outside air temperatures.

I would have thought the maximum difference would be the difference in outside air temperatures; I actually was thinking there would be no difference as the fluid is cooled.

What am I missing?

P.S. When running on the highway empty I generally see 120F to 140F depending on winter/summer.

Thanks!

 

[RikDavis]

I have not watched my temps a lot but I did check it climbing a 2 mile grade with my 5000 lb trailer a couple days ago. The outside temp was in the mid 80's and the transmission temp was pretty steady at 168. Coolant ran from 190 to 200 and the oil was constant at 199 so that would appear to be about the same as yours

 

[Gonzo 1066]

I have 12,000 towing miles on my 2013 now. I have NEVER seen the trans temp over 200 degrees while towing in the mountains CGVW at 29,000#. On the flat it runs somewhere between 170 and 185. I think you are seeing a VERY good LOW temperature with your truck..

 

[Wertles]

The 2013+ will actually warm the fluid up to 165 for efficiency purposes. I don't believe that was on previous models. I have gotten to 193 in stop and go traffic in 90 degree weather. I don't think I would start worrying until I started to see 230+.

 

[RUSSELL5000]

Thanks for the input. I'll watch, but it seems to be very consistently in that temperature range. It also does not seem to matter whether I am towing the small cargo trailer for the boy scouts or my travel trailer.

 

[Too Tall]

Ambient temp is a factor but the biggest is load. If you were traveling faster or bucking a headwing, it would cause higher temps.

 

[RUSSELL5000]

I took the boy scouts on a trip this past week. The boy scout trailer is a light load for the truck - only about 5,000 pounds.

The EVIC showed a fluid temp of 168 at the highest when we returning - the EVIC showed an outside temperature of 95 degrees F. A couple hundred miles west and through some rain and a storm front, the EVIC showed an outside temperature of 73 degrees F. The EVIC showed the transmission fluid stabilized at about 158.

It was windier prior to the storm front; I'd say terrain was similar.

This was about ten hours of constant driving - only bladder stops.

I find that I really like how comfortable the truck is to ride in and how well the exhaust brake works. What a great truck.