Bigger transmission cooler, will it run hotter?

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Nick1994

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I'm thinking about installing a bigger transmission cooler on my Jeep, it has a factory one but it's the cutest thing you ever saw. It's a common upgrade, but I worry about airflow for the radiator. My Jeep runs pretty hot at low speeds, 230 degrees or so. I'm concerned that putting a big transmission cooler on it will reduce radiator air flow, and might make it run hotter.

Is this possible?

BTW, the entire cooling system has been replaced, not concerned with that.
 
Originally Posted By: Nick1994
I'm thinking about installing a bigger transmission cooler on my Jeep, it has a factory one but it's the cutest thing you ever saw. It's a common upgrade, but I worry about airflow for the radiator. My Jeep runs pretty hot at low speeds, 230 degrees or so. I'm concerned that putting a big transmission cooler on it will reduce radiator air flow, and might make it run hotter.

Is this possible?

BTW, the entire cooling system has been replaced, not concerned with that.

At low speeds it is. I recall helping my brother install one years ago on his pick up truck for towing the boat. In traffic [boat not in tow] the engine actually ran hotter, with the boat is was worse. Moving along at normal driving speeds it was fine. I have a feeling that is what might happen to your Jeep.
 
Grab yourself the 2.5L clutch fan, and your low speed worries are over. It will sound like a semi truck, but the cooling will be significantly improved. Threw one on my 4.0, and my electric fan is forgotten. Even with the top of the shroud broken, there is a big improvement in air flow.
 
Originally Posted By: Dyusik
Grab yourself the 2.5L clutch fan, and your low speed worries are over. It will sound like a semi truck, but the cooling will be significantly improved. Threw one on my 4.0, and my electric fan is forgotten. Even with the top of the shroud broken, there is a big improvement in air flow.
Already have one, thanks.
 
Now I don't know how good of a cooler you can cram, but if I was desperate to get my temps down I would get a low profile wide cooler into the space allocated for the optional OEM winch. You can mangle up the center portion of the bumper to get air flow, or put fans on it, but you would be limited on fan choices there I would imagine.

Now this is a non-hillbilly option, you could always grab a window unit A/C, gut the innards and plumb the ATF to run where the R410 did
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If only you were not in AZ, you could convert the A/C to OBA (it is one of the most easy and useful mods ever), and use the A/C condenser for the cooling.
 
I have a B&M cooler on my Jeep. If you run the cooler so it is separate from the radiator heat exchanger, your coolant temps might actually be cooler. The AW4 transmission runs fairly hot, and the factory setup is to run it through a heat exchanger in the radiator and then through the tiny cooler you have for specific option packages. Since you live in AZ, you don't need the heat exchanger which essentially warms the transmission fluid for cooler climates.
 
No experience with jeep but they make those heat sink type coolers I’ve seen on land rovers. They are long and look like they’d dissipate a lot of heat for the size. If I had an automatic transmission I might think about doing that. I might do something for the new to me Buick. Just haven’t taken a look yet.
 
I have a pretty large (5 row?) transmission cooler on my Cherokee along with another transmission cooler for the power steering fluid. No over heating issues. I was off roading with it in 100 degree heat and it never went above 210.
 
Originally Posted By: ARB1977
You can also add a bigger transmission pan for more capacity.

Those work pretty well. The location of the transmission cooler is important, if it interferes with part of the radiator it can cause engine temps to rise, which I believe was the case with my brother's. In a location where it doesn't it can lower operating temps. I didn't make that clear in my last post. It was a long time ago when we messed with it.

OT-I installed grill inserts in my Rubicon to protect the radiator. Some people swear they don't cause them to run hotter. Not so in my case I took them out, temps in the summer in traffic climbed higher and faster. It went back to normal removing them. Maybe those swearing they didn't cause them to run hotter didn't have the EVIC.
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Unless your trans cooler is half as big as the rad or larger, I dont think itll cause too much of an issue with engine temps rising. The hot air from the AC condenser would probably create more heat than the trans cooler. Usually typical trans coolers are probably the size of a smaller book, if you can tuck that low or off to the side you should be able to fit it without any issues. Ive seen Jeeps come in that have the cooler attached to the frame rail for protection from rock etc when offroading, and it made a huge difference, even not being in the front of the car. Radiant cooling can make a difference.
 
whole cooling system replaced? what radiator did you use? Some of the aftermarket ones will make it run hotter.
 
Just need to add some Water Wetter additive to coolant. 20 degrees cooler with additive alone. Or try Purple Ice, Bath Salts.
 
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Don't turn your nose up at the small factory cooler. I bought an OEM cooler to add to the in radiator cooler on my Suburban. When it came, I almost sent it back and bought a B&M or something. I called a friend who owns a transmission shop and he told me the OEM ones are extremely efficient and work really well.
Turns out, he was right. Trans is much cooler than before and my trans oil lasts much longer than before the cooler install.
You'd never believe it based on the physical size of the cooler.
 
Depends on the construction of the cooler.

All else equal, size is a factor. When I bought a bunch of coolers for my delivery trucks, I had a lot of fun looking at the BTU ratings of various coolers. The new ones I have reject 7 times more heat than factory, under similar conditions of testing.
 
Nick,

Are you wanting a bigger cooler because ATF temps are high, or just because the factory cooler looks small?

A lot of the stacked-plate coolers like Tru-Cool and B&M have two different thicknesses. You could probably find one with a similar footprint but twice the thickness of your current cooler. (I'm imagining the tiny little cooler on my Silverado here. I don't know what your Jeep's looks like.)
 
Originally Posted By: Rhymingmechanic
Nick,

Are you wanting a bigger cooler because ATF temps are high, or just because the factory cooler looks small?

A lot of the stacked-plate coolers like Tru-Cool and B&M have two different thicknesses. You could probably find one with a similar footprint but twice the thickness of your current cooler. (I'm imagining the tiny little cooler on my Silverado here. I don't know what your Jeep's looks like.)
I don't know what the trans temp is, I just figured in my extreme climate it might be beneficial to have a bigger cooler.
 
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