GM Yukon XL Denali Transmission Temps
My main tow vehicle is my RAM CTD, but when we take the RV as well the truck has to pull my 7000 pound boat. So then we use my 2011 Yukon XL Denali to tow the Malibu. It has always run hot - both...
Forum Discussion
bartlettj wrote:
Since the engine and transmission cooler share space, keeping the engine cooler helps too. Higher revs are actually better for this, so let it shift and rev if it needs to. Make sure the thermostat, radiator cap, and coolant are in good shape, as well as the ignition system.
This. From the factory the run the trans fluid through the radiator cooler first, then the external cooler.
My trans temp, as per a scan tool, usually matches the engine temp pretty closely when climbing hills...AS LONG AS the torque converter is locked.
Once the converter unlocks the trans temp can start creeping up.
Your truck is already running at 220 normally, so if it is getting warmer than that pulling those killer hills you have our there, it is not a stretch to think it would hit 250-260. I feel like that is high, but I'm not an engineer that designed the thing. :)
My truck runs around 180-185, sometimes slightly warmer pulling hills. Rarely hits 200. But this is because I have a 175 thermostat in it rather than the factory 195.
I think the ECU intervenes at 270 trans temps and gets more aggressive with torque converter lockup.
Make sure you don't have a bunch of leaves and bug buildup in the cooling stack. I found a whole bucket of leaves between the AC condenser and the radiator when I had to replace the radiator a few years ago. Cleaning that out helped me a lot.
