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Transmission cooling.

Babaganoosh

Babaganoosh

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As most know I'm hard on my trans...

It currently will creep up over 200 on a long drive even seen 230 in the hills. Trying to make it last and want to try and get it under 200 for the hills. My current setup is just this trans cooler in front of the radiator. https://www.summitracing.com/parts/...19QIVYB6tBh09UgzmEAAYASAAEgIunPD_BwE#overview

I know on paper it should be ran through the radiator then through the cooler, but will this be the fix or adding a 2nd or bigger cooler be the answer?
 
Give it a chance and plumb it correctly (through the radiator) first. Liquid cools more efficiently than air.

I had the same problem when I bypassed the radiator and we run the same cooler IIRC.
 
You can never have enough cooling. Either get a bigger external cooler with a fan or run it through your radiator to add capacity.
 
I second that, from a purely scientific standpoint. Heat transfer is much more efficient with fluid. But you may want to check out how @Wes Harden set up his sub, he tows up some pretty good inclines and has no radiator cooler on his. Remember, that heat is going somewhere. If its running through your radiator, it's going to make the coolant that much harder to cool, and you may end up with higher engine coolant temps.
 
I ran my 700r4 through a factory cooler in the radiator on my K5 and never worried about it. Granted I have a giant 6.2 diesel sized radiator so the trans cooler is huge too. Driven in the desert in 100+ degree days and engine temp never got over 190 degrees. I never had a temp sensor on the trans fluid. But I will say this the trans fluid was perfect when I pulled it. No signs of overheating by color or smell.
 
1644517468663.pngbal/images/prod/xlarge/der-54008_af_xl.jpg


Im not sure if this is the exact one I have but I know I bought the largest Derale plate style one that they made at the time for my 400 in my K5. I just have it mounted infront of my engine radiator (no dedicated electric fan). I rarely see my tranny temps go above 180 trail riding in the summer in Wisconsin so 80*-90* temps. Not sure about street driving or towing. I feel that the plate style are much more efficient. I don't remember it being so expensive?
 
skunked said:
Give it a chance and plumb it correctly (through the radiator) first. Liquid cools more efficiently than air.

I had the same problem when I bypassed the radiator and we run the same cooler IIRC.
Click to expand...
This is what I was afraid of, I would need a new radiator to plumb it correctly. With all the bad posts on here it scares me to get rid of the radiator I have now, even though it's 31 years old but all STEEL.
 
Babaganoosh said:
This is what I was afraid of, I would need a new radiator to plumb it correctly. With all the bad posts on here it scares me to get rid of the radiator I have now, even though it's 31 years old but all STEEL.
Click to expand...

The radiator doesn't have the provision or it's full of transmission guts still? Pull it, have it hot tanked if it has a cooler. Otherwise, there's other radiator options out there.
 
skunked said:
The radiator doesn't have the provision or it's full of transmission guts still? Pull it, have it hot tanked if it has a cooler. Otherwise, there's other radiator options out there.
Click to expand...
The guts is what killed a few transmissions and it's a 4 core big block radiator that has been extremely good.
 
Babaganoosh said:
The guts is what killed a few transmissions and it's a 4 core big block radiator that has been extremely good.
Click to expand...

pull it, have it cleaned at a radiator shop and plumb it properly. I run the same radiator in the 84K10 with the same trans cooler however I'm working with a BBC and TH400.
 
I run the small CBR https://www.cbr-performance.com/oil-coolers/ with spal fan. Its pretty damn thick, so this may not fit at all. Temp switch and manual bypass switch. No additional radiator cooler. I do run an aluminum pan on my 4l80e, and that can make a difference.

You're converter choice has a huge effect on what cooling system you'll need to run. Not to mention how the fan is setup. Whether you push or pull, and have obstruction from going through the rad too. My stack in this area is FRONT< [Trans cooler][SPAL fan][Radiator][SPAL fan] >ENGINE. Operation for rad fan is the trans cooler is in front of my high-temp on rad fan. So normally the rad fan is not helping the trans fan.

What's really needed is a true BTU rating on some of the coolers, but alas, you don't often get that, nor can you trust the numbers if you did.
You're also in Phoenix, I'd get two.
 
I have the derale cooler in front of the radiator( fan in front of the cooler pulling through then radiator, then 2 big 16 inch derale spal fans.
 
I bought the biggest stacked plate cooler I could find on Summit. IIRC it's basically 11" square. I have an electric fan on it that is mounted like @Tnsejed behind the cooler or between the cooler and radiator. It's wired with a temperature switch. The fan is only needed for rare occasions on the trail.

For a short time I tried a smaller trans cooler to allow more air flow thru the radiator. The transmission ran noticeably warmer so I switched back to the big one.

As @Tnsejed mentioned, the torque converter plays a huge role. As soon as my converter locks up, I can see the trans temp drop quickly. This is true on the highway and on the trail. One of the reasons I like the 454 and Magnum set up is that I can run most of the time in 2nd and 3rd gear which allows the converter to lockup. I also saw a big advantage with the BBC pulling the mountain passes because I can put the trans in a low gear and lock up the converter so I have enough torque to pull the grades and the locked up converter keeps the trans temps down along with engine RPM. Even with all of the engine cooling issues I have pulling a camper over the passes, the transmission rarely gets to 200°F.

I have the standalone trans controller which has allowed me to tweak how the converter locks up so I don't know how it compares to a factory type strategy. In my experience that lockup converter is one of the biggest aids to keep the trans cool. Usually I'm cruising with a trans temperature between 165° and 170°.

I started out with mine bypassing the factory cooler in the radiator. I decided it plumb it in more for the winter time to get the trans to warm up a little more. I didn't really notice a huge difference in summer time operating temperatures.
 
Going off of my 2019 Colorado, cause I have engine and trans temps readily available. Not sure if it has a trans cooler after radiator, I’m thinking it might just be a 10“ section of aluminum that’s finned after it runs through the rad. I do tow up to 3k lbs occasionally.

Point is, the tranny has never been over 155. And the engine runs at 205 all of the time. thats my only scientific evidence. But it suggests to me, that there is little if any heat exchange happening in the radiator and that the radiator is cooling both fluids when everything is at temp. Hence, I did what most have suggested and run the trans fluid through the radiator, then the external cooler.

I recently replaced the rad in my K5, went with Mishimoto aluminum 3 core ( they sure are pretty), had to modify the mounts and shroud, I have the AC condenser in front of the rad with a Derale plate style mounted in front, just the stock fan on the stock motor. Since I installed the new rad, I haven’t seen the engine temp over 170 after the thermostat opens. No idea what the trans temps are though.
 
IMG_20210811_133626.jpg

Derale 62000 btu cooler, not plumbed through radiator.
Ground side manual switch. Takes along high speed run towing up hill get it over 200.

Before plumped through radiator, then to stacked plate w/fan. Ambient temp over 115*. towing the boat back from lake would peg my trans temp at 240. Engine temps would creep up over 210. Add in heat from ac condenser.
Low speed, residential driving 500 ft elevation gain. Even not towing engine temp would climb with or without ac on. Very related as soon as by passed the radiator eng temps improved greatly. Trans temp were better, but I wanted more so I went with the biggest off the self remote cooler I could get.

Now engine never goes over 190
Trans stays between 140-170 normal, not towing.

IMG_20210811_133626.jpg

20201014_182654.jpg
 
Babaganoosh said:
I have the derale cooler in front of the radiator( fan in front of the cooler pulling through then radiator, then 2 big 16 inch derale spal fans.
Click to expand...

You'll be able to get it without plumbing through the rad if you don't want to. Going through the rad would solve it but sometimes you just can't. There is no reason not to either go for a much bigger cooler, or run two coolers, or even three. Depending on what you want to do, you could get a bigger cooler or add another one. Getting a smaller second cooler with its corresponding fan and mounting it under the truck is an option as well.
 
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