Keeping coolant and transmission temps under control when towing in the summer heat

[Doubeleive]

I drove it a few more miles today fairly heavy on the pedal in town driving, it slowly heated up 187, then I let it sit in the driveway and idle for 5-10 minutes and it cooled down slowly to 183, 90 deg's outside
typically before in front of the radiator/fans it would have warmed up to about 165-170 maybe
I guess I need to take it down the highway a bit and make sure it's not going to just get hotter and hotter, see if it holds at a certain temp.

 

[gooffeyguy]

I was originally going to install a Tru-Cool last year, but after getting one and realizing how much of the radiator it was going to cover, I went with a Derale 10000 series stacked plate

It's the same width as the stock one that came on my Denali, but it's about twice as tall. It goes all the way up to just under the hood latch mechanism. It's about 2x thicker too. It's rated at 46,000 btu.

I haven't towed anything substantial up mountains or at high elevations yet though

 

[Geotrash]

I drove it a few more miles today fairly heavy on the pedal in town driving, it slowly heated up 187, then I let it sit in the driveway and idle for 5-10 minutes and it cooled down slowly to 183, 90 deg's outside
typically before in front of the radiator/fans it would have warmed up to about 165-170 maybe
I guess I need to take it down the highway a bit and make sure it's not going to just get hotter and hotter, see if it holds at a certain temp.

That's about perfect and what I would expect. I'll also bet that you'll stay nice and cool on the highway with the airflow through it.

 

[Geotrash]

One more data point here. I towed the camper with the '07 XL Denali yesterday for the first time in a long time, which still has a Tru-Cool 40K mounted in front of its OEM radiator (the '12 is the one I usually tow with which has the Derale cooler mounted below the bumper and has a Cold Case radiator). Ambient temp was 85ºF and I was taking it from our house back to storage but took it down I-64 several miles for fun. Trans temp stayed less than 150º the whole trip, but the coolant temp shot up to 230º in a few spots with barely any hills. Just more evidence that mounting that Tru-Cool 40K in front of the radiator is disastrous to engine cooling when towing. Going to either move that Tru-Cool to below the bumper or put in a Derale like the other one.

 

[Doubeleive]

Roaming around town today pretty warm out, seems to be hanging around twice the ambient temp

 

[Tallpaulboise2]

Update after test drive: Took the Yukon out for a little highway cruise to get it up to temperature this evening. Ambient air temp was 70ºF. The transmission temperature gradually climbed and held steady around 175º on the highway after 20 minutes or so. Then getting off the highway and going through traffic, the temp crept up to 185º. I stopped in a parking lot to check the cooler fan and it wasn't running yet. It didn't kick on until the indicated transmission temp was between 190º and 195ºF (stopped again to check when it was 194ºF), but it quickly stopped the rise and started bringing it back down. I shut the engine off and after a minute or so the fan stopped with the temp back down around 182ºF indicated.

Curious what those of you running this cooler are finding with it, where it keeps your temp with and without towing, and whether the fan brings your temp back down when towing up a grade effectively. Thanks for your thoughts.

How loud is the fan on the Derale? I moved my trucool below the bumper and will tow over 6000’ this weekend. I found my trans temps at 150 on the highway at 99 outside temp, about 170 after sitting idling for 15 minutes. I’m thinking , and will find out this weekend if I need to put a fan behind the trucool for the slower mountain towing. I have been looking at Derale’s fans in case I need one. How do you post pics?

 

[Geotrash]

How loud is the fan on the Derale? I moved my trucool below the bumper and will tow over 6000’ this weekend. I found my trans temps at 150 on the highway at 99 outside temp, about 170 after sitting idling for 15 minutes. I’m thinking , and will find out this weekend if I need to put a fan behind the trucool for the slower mountain towing. I have been looking at Derale’s fans in case I need one. How do you post pics?

It's audible, but not from inside the truck so it's not as loud as the main cooling fans by any means. I'll pretty much guarantee your Tru-cool will be plenty to keep your trans temps below 230, even towing up a 7% grade for miles, as long as it has good airflow through that lower bumper fascia. It's so much more effective than the factory cooler.

As for pics, if I'm using a computer, I take a screenshot of the image and paste it into my post in the browser. If I''m using my mobile phone, I use the insert picture feature on the forum and select them from my camera roll.

Please do keep us posted on what you learn!

 

[alpha_omega]

Have you guys seen this or one like it. Granted we are all partial to either the Tru-Cool or the Derale, but this design seemed like a great idea for mounting in the lower bumper area.

Moroso 41205: Heavy Duty Transmission Cooler/Filter | JEGS

Buy Moroso 41205 at JEGS: Moroso Heavy Duty Transmission Cooler/Filter. Guaranteed lowest price!

www.jegs.com

 

[Geotrash]

Have you guys seen this or one like it. Granted we are all partial to either the Tru-Cool or the Derale, but this design seemed like a great idea for mounting in the lower bumper area.

Moroso 41205: Heavy Duty Transmission Cooler/Filter | JEGS

Buy Moroso 41205 at JEGS: Moroso Heavy Duty Transmission Cooler/Filter. Guaranteed lowest price!

www.jegs.com

View attachment 344646

I considered this type of cooler, but it's also passive and couldn't find the BTU rating for it anywhere. Hard to believe that it would cool as well as a plate and fin style cooler does.

 

[Doubeleive]

How loud is the fan on the Derale? I moved my trucool below the bumper and will tow over 6000’ this weekend. I found my trans temps at 150 on the highway at 99 outside temp, about 170 after sitting idling for 15 minutes. I’m thinking , and will find out this weekend if I need to put a fan behind the trucool for the slower mountain towing. I have been looking at Derale’s fans in case I need one. How do you post pics?

be sure to post back what it does, mine has been up to 203, ambient was about 110. I am sure part of that has to do with how I drive it. I see there are some smaller 80w fans on ebay I have been mulling over hooking up one of those if need be.