[69gmcc10]

So...About that transmission temp issue.

One of the biggest reasons I sold the green truck and bought this truck was because I wanted the tough and robust 4L80E for towing heavier loads. I have been towing quite a few vehicles on my car hauler and a few utility trailers, but nothing over 6000 lbs, and truck seems to handle it just fine, but every time I tow over one of the passes (where I live I cant go more than 100 miles without needing to go over a pass) I would inevitably get some trans heat and see some numbers push 230 deg. Depending on who you talk to safe trans temps range from the high end of 240 to "you should never let your trans temp exceed 200," but regardless of max safe temps they all agree that cooler is better.

On the week surrounding the 4th of July the wife and I loaded up a toy hauler with a side by side and headed on a 6 hr drive to go camping. Over that week temps here were hot, hot for Montana (high 90's) and we had to go over 3 passes of about 2000 ft of elevation change. We were loaded right close to the max gcwr for the truck, not that the magical 14,000 lb number would have stopped me form adding more if needed, but I was not over. Trans temps ran high all day long and when we went over the passes it was getting hot! On the flats the trans temps didn't drop below 190 and on the passes even slowing down significantly to try and keep temps down it would climb to 240, not good.

So, I came to the forum under the Engine and Drivetrain section and started asking questions. I got some good answers and Clinebarger pointed me in the direction of the the Tru-Cool Max trans cooler as an upgrade to keep those temps down. It appears to be the answer to my problems so I ordered it up.

This cooler is big! It is 3x the size of the stock cooler and since I live in a place that can see some real cold temps at times I also got a trans cooler thermostat that bypasses the radiator until trans temps get up to 180ish.