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

[Geotrash]

It would be interesting to know how much of a difference the new baffles on either side of the radiator made.

Hard to say since I changed 2 things at once. But, I did notice that on the highway my temp gauge never got out of the center spot, when it used to get between 1/2 and 3/4 before I fixed the baffles. I didn’t have the OBD2 dongle hooked up, so I don’t know the precise coolant temps from this trip. But it seems that routing the transmission fluid through the radiator’s cooler hasn’t had any negative effect on coolant temp.

 

[Geotrash]

Small update here. Drove back over the mountain today on the way home but today it was 90° outside. Strangely, the transmission ran even cooler today, topping out at 226°F on the steep eastbound climb. The coolant temperature spiked briefly at about 230°, and then shot right back down as the fans kicked in, staying around 217° for the remainder of the climb. On the highway, I never saw above 210° for coolant temperature, and the transmission stayed around 190°. So, it seems that the new baffles have dropped the coolant temperature between 5 and 7°, all else remaining equal.

 

[thompsoj22]

Small update here. Drove back over the mountain today on the way home but today it was 90° outside. Strangely, the transmission ran even cooler today, topping out at 226°F on the steep eastbound climb. The coolant temperature spiked briefly at about 230°, and then shot right back down as the fans kicked in, staying around 217° for the remainder of the climb. On the highway, I never saw above 210° for coolant temperature, and the transmission stayed around 190°. So, it seems that the new baffles have dropped the coolant temperature between 5 and 7°, all else remaining equal.

Im coming in late on this conversation, My baffles are toast also and id like to simply replace with oem, Did you replace/repair/manufacture your replacements?

 

[thompsoj22]

Well all, I think my cooling issues are resolved when towing. We made the same trip over the blue ridge mountains I made a few weeks ago, and the transmission temp topped out at 232º yesterday at the top of the pass. Last time was before I plumbed the radiator's cooler back into the system and it hit 263, so this is a 30º improvement. Coolant temp topped out around 215, all at 80ºF ambient. Rolling on the highway I was steady between 190 and 196 depending on the terrain. Gonna keep the Derale. set up this way it's the perfect solution, in my opinion.

I would not have thought that running the DERALE as a stand alone without the radiator in the circuit would have decreased its ability to control the trans temp? I stll have the radiator loop in my setup and felt i should have eliminated it. Maybe i should just leave it alone, I have been known to fix chit til it breaks!

 

[Geotrash]

I would not have thought that running the DERALE as a stand alone without the radiator in the circuit would have decreased its ability to control the trans temp? I stll have the radiator loop in my setup and felt i should have eliminated it. Maybe i should just leave it alone, I have been known to fix chit til it breaks!

Me either, but that’s definitely what my data shows - by a significant margin of 30-40°F on the same mountain climb, with similar ambient temps, and also 10-15°F on the highway.

On the baffles, I made mine from scratch from black coroplast sheet, and used zip ties to hold them in place.

 

[03_GMC]

Small update here. Drove back over the mountain today on the way home but today it was 90° outside. Strangely, the transmission ran even cooler today, topping out at 226°F on the steep eastbound climb. The coolant temperature spiked briefly at about 230°, and then shot right back down as the fans kicked in, staying around 217° for the remainder of the climb. On the highway, I never saw above 210° for coolant temperature, and the transmission stayed around 190°. So, it seems that the new baffles have dropped the coolant temperature between 5 and 7°, all else remaining equal.

That’s good news brother!! I’ve been MIA due to no cell coverage and spotty internet. First since you saw temps in your trans around 260 before I’d recommend doing a fluid change. Most ATF breakdown over 240.

So I definitely need to do baffles. If I choose to keep this as my tow pig I will also have to upgrade the radiator. We are in Casper WY for the night and today we drove from Grant Campground in Yellowstone to Casper via US26. There was some pretty gnarly climbs between Grant and Riverton. My trans never went above 225 but I still get coolant spikes up to 240ish and then it will cool back down. Also that weird fluid leak happened again on the drivers side. Not as much this time and it’s definitely hydraulic smelling fluid like power steering, brake, or shock. Not too sure what to think about that but oh well. After this trip though I am really considering a Duraburb or an Express van.

 

[Geotrash]

That’s good news brother!! I’ve been MIA due to no cell coverage and spotty internet. First since you saw temps in your trans around 260 before I’d recommend doing a fluid change. Most ATF breakdown over 240.

So I definitely need to do baffles. If I choose to keep this as my tow pig I will also have to upgrade the radiator. We are in Casper WY for the night and today we drove from Grant Campground in Yellowstone to Casper via US26. There was some pretty gnarly climbs between Grant and Riverton. My trans never went above 225 but I still get coolant spikes up to 240ish and then it will cool back down. Also that weird fluid leak happened again on the drivers side. Not as much this time and it’s definitely hydraulic smelling fluid like power steering, brake, or shock. Not too sure what to think about that but oh well. After this trip though I am really considering a Duraburb or an Express van.

Sounds like a Cold Case radiator might be in your future, though 240 is still 25º less than red line. That fluid leak is weird. Seems to happen when you're running it pretty hard.

Glad y'all are having a good trip so far. Yellowstone is pretty spectacular. We'll be traveling 287 from Lander until we pick up 26 into Grand Teton NP, and then again on the way out from Shoshone to Casper. Drove those roads many times back in the day. Goes past a place called Hell's Half Acre west of Casper that was pretty entertaining to look at, as I recall.

I was seriously considering a conversion from Duramax Specialties, but with this thing running so well now, I'm going to keep rolling with it.

 

[03_GMC]

Sounds like a Cold Case radiator might be in your future, though 240 is still 25º less than red line. That fluid leak is weird. Seems to happen when you're running it pretty hard.

Glad y'all are having a good trip so far. Yellowstone is pretty spectacular. We'll be traveling 287 from Lander until we pick up 26 into Grand Teton NP, and then again on the way out from Shoshone to Casper. Drove those roads many times back in the day. Goes past a place called Hell's Half Acre west of Casper that was pretty entertaining to look at, as I recall.

I was seriously considering a conversion from Duramax Specialties, but with this thing running so well now, I'm going to keep rolling with it.

Do you by chance have a link to the cold case??

 

[Sparksalot]

Do you by chance have a link to the cold case??

2012 GMC YUKON XL 1500 Cold Case Radiators GMT569A Cold Case Performance Aluminum Radiators | Summit Racing

Free Shipping - Cold Case Performance Aluminum Radiators with qualifying orders of $109. Shop Radiators at Summit Racing.

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[Geotrash]

2012 GMC YUKON XL 1500 Cold Case Radiators GMT569A Cold Case Performance Aluminum Radiators | Summit Racing

Free Shipping - Cold Case Performance Aluminum Radiators with qualifying orders of $109. Shop Radiators at Summit Racing.

www.summitracing.com

Thanks Rex. That's the one!