ATF gets too hot

Turtle n Peeps wrote:
225 is not "too hot". Nothing is wrong with your truck. Go on vacation and have fun.

x2

I had the same concerns the other week. I'm towing about 7500# Jay Flight 28BHBE w/ a 2012 burb 5.3 w/towing package. Went to Disney down I-95 doing about 60-63 MPH. Outside temps were a steady 102 and trans temp leveled out at 216 for our 8 hr drive. engine temps rose to about 220ish, but was steady. I did have my trans fluid changed (not flushed) and a new filter just for the trip. Trans temp was one of my biggest concerns...getting stuck in traffic in hot weather, just creeping along. But we survived.

Transmission fluid temps (TFT) of my TV is something that has been of concern to me as well. For awhile now, I have been reading a lot on a couple of diesel truck forums. One thing I learned is that the TFT varies greatly depending on where it is measured, and in this thread this very important factor has not been mentioned:

Is it measured from the OBDII plug in the vehicle (this is where I pull TFT on my truck), and if so, where is the vehicle computer measuring it?

From the transmission fluid pan?

From the hot outlet just before the ATF goes into the transmission cooler?

Where the fluid comes out of the transmission cooler?

From what I have read, one will get widely differing temperatures depending on where it is measured. Some truck owners on some of the diesel forums have more than one gauge and pull TFT in more than one place. FYI, I have read more than once that a larger transmission pan didn't really make much of a difference in TFT.

So throw that important factor into the discussion. If for example, one person measures it at the hot outlet of the trans, and someone else at the outlet of the trans cooler, then we are comparing apples to oranges.

Totally normal for 2014 GM. It has Dexron VI fluid which can handle much higher temps than previous fluids and IIRC, the factory will tell you normal temps for towing are 200-235 with a max of 265.

In another article I read,

In the February 2011 issue of Trailer Life magazine RV Clinic in response to a reader about the maximum transmission temperature allowed in a 2009 Chevy Silverado, the Tech Team had this response.

“General Motors’ in-house towing team expert provided RV Clinic with this statement: The maximum allowable automatic transmission fluid temperature is dictated by the transmission oil itself. The oil begins to degrade significantly above 270 degrees Fahrenheit, so we design vehicles so that in all but the most extreme conditions, the fluid temperature in the transmission sump stays below 270 degrees F.

We allow for up to 285 degrees F in extreme conditions (i.e. towing a trailer with combination loaded at GCWR in Death Valley). But for customer usage anywhere else in the country, even at GCWR, transmission sump temperature should stay well below 270 degrees F. Above this point, certain internal components, such as seals, begin to disintegrate rather quickly. Although newer synthetic fluids can withstand higher temperatures we still recommend this (270F) as a maximum temperature. "

Sounds pretty normal to me. When you are trying to maneuver into a spot using 1st and reverse gears, the torque converter does not lock in these gears and just remains in fluid coupling. It doesn't take long for the temperature to get up there. As others have said, 4Lo gives the transmission a lot more leaverage and will help keep temperatures down. Tow Haul does nothing for you in this situation.

Tystevens wrote:

Turtle n Peeps wrote:
225 is not "too hot". Nothing is wrong with your truck. Go on vacation and have fun.

This. 225* is just fine.

X3.

Turtle n Peeps wrote:
225 is not "too hot". Nothing is wrong with your truck. Go on vacation and have fun.

This. 225* is just fine.

225 is not "too hot". Nothing is wrong with your truck. Go on vacation and have fun.

I used a 2014 Silverado that was under GM's captured test program to haul a couple of tram's to the county fair from an apple orchard. It was 95 degrees out, and I never went above 25 mph. The transmission ran around 230 degrees. I reported it to the engineers, who indicated that was within spec and expected because of the slow speeds.

All these responses are really appreciated. I always have the transmission in tow/haul mode when towing. I will try the Lo range next time when maneuvering it into place.