Transmission cooler for 2021 Tahoe

[topaq]

Just so we can compare apples to apples, what do you mean by 'tough'? What was your fluid temp by the time you got to the top of that pass? How heavy is/was the trailer you were towing?

At one point got up to about 240-250 degrees. Short of the red line. Towing a trailer that at scale is 6700lbs loaded max. Maybe a little less since this was the return trip and we had left some items behind with relatives. Very warm day, steep climb that slowed us down to 45-50 mph on the uphill so not a lot of airflow. Lots of ups and downs so it would quickly cool off only to go back up again on the next hill.

 

[Geotrash]

At one point got up to about 240-250 degrees. Short of the red line. Towing a trailer that at scale is 6700lbs loaded max. Maybe a little less since this was the return trip and we had left some items behind with relatives. Very warm day, steep climb that slowed us down to 45-50 mph on the uphill so not a lot of airflow. Lots of ups and downs so it would quickly cool off only to go back up again on the next hill.

Yup. Got it. It’s uncomfortable to see but it’s normal.

On the earlier Denali’s, the problem we’ve run into with aftermarket coolers is that adding a larger than stock cooler in front of the radiator has the unintended consequence of reducing engine cooling capacity and raising engine coolant temps… so much so that guys have gotten engine temperature warnings and had to stop.

So, my opinion is that the best solution beyond factory is one that cools the transmission fluid more than the factory setup can, but not as much as a much big cooler like the Trucool 40k will. I’m my case, I mounted a Derale 13960 fan-forced cooler below the front bumper and it’s the perfect setup. Again, in my opinion

 

[topaq]

Yup. Got it. It’s uncomfortable to see but it’s normal.

On the earlier Denali’s, the problem we’ve run into with aftermarket coolers is that adding a larger than stock cooler in front of the radiator has the unintended consequence of reducing engine cooling capacity and raising engine coolant temps… so much so that guys have gotten engine temperature warnings and had to stop.

So, my opinion is that the best solution beyond factory is one that cools the transmission fluid more than the factory setup can, but not as much as a much big cooler like the Trucool 40k will. I’m my case, I mounted a Derale 13960 fan-forced cooler below the front bumper and it’s the perfect setup. Again, in my opinion

That's kind of the way I'm leaning.

 

[futbalclub]

Another update. I recently finished another cross-country (North Carolina to California and back) trip towing a ~5700lb (dry weight) travel trailer and can confirm that, at least for my situation, the stock transmission cooler is quite sufficient. I only saw the temperature go above 180 degrees on 3 or 4 occasions. The highest it got was just a little over 200, and that was only very briefly on I-70 Easbound west of Denver climbing the first of 2 10,000+ ft mountains. The other couple times it topped out at around 190-195. The trip went over a LOT of big hills, as you might imagine, and many of them were in 90+ degree heat. I can confirm that the Tahoe (2021, 5.3 V8) was more than up to the task of an 8600+ mile round trip. No issues at all. It's a *very* comfortable way to go across the country carrying 4 people and 2 dogs.

 

[Bigkevschopshop]

Personally I would see if you have any area under the vehicle you can slide this little jewel in. Both of these I would suggest running in series with the cooling system you have there, both will do a job of lowering temps, the heat sink will be the lesser of the two but takes less to install no wiring etc and will add a little capacity also. I have run both on OT vehicles with good results. The heat sink style I ran on a car 3 inches off the ground mounted to the frame rail and kept the auto trans in line. The remote cooler with fan is good mounted anywhere underneath, the fan should be thermostat controlled and will turn on at a certain temp and off at another. This solution gives you more than enough with the stock cooler up front, than swapping to the bigger cooler up front and hurting engine cooling.

Summit Racing SUM-331000 Summit Racing™ Heat Sink Transmission Coolers | Summit Racing

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Derale Cooling Products 15850 Derale Atomic-Cool Remote Fan-Mounted Oil Coolers | Summit Racing

Free Shipping - Derale Atomic-Cool Remote Fan-Mounted Oil Coolers with qualifying orders of $109. Shop Fluid Coolers at Summit Racing.

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