Aux trans cooler

[LM7Yukon]

Does the aux trans cooler on a Yukon have 1 line to the transmission and another to the radiator? How does it differ to not having an aux cooler and using the built in from the radiator?

[GM-Tech]

Even with the aux. cooler, trans fluid still goes throught the cooler built into the radiator. They don't want the trans to run too cold.

 

Radiator temp usually won't exceed 210-220, whereas under severe conditions (towing, etc.) the trans can easily exceed that. This is where the aux. cooler comes into play.

[LM7Yukon]

Even with the aux. cooler, trans fluid still goes throught the cooler built into the radiator.  They don't want the trans to run too cold.

 

Radiator temp usually won't exceed 210-220, whereas under severe conditions (towing, etc.) the trans can easily exceed that.  This is where the aux. cooler comes into play.

 

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Mine didn't come with the aux cooler, so the dealer installed the accessory model which looks like OE, and fits in same place as OE. However, it doesn't appear that the internal radiator cooler is being used anymore, or this isn't connected right.

 

How can i tell?

[GM-Tech]

One of the lines from the aux. cooler should go to the cooler in the radiator. If they put the GM accessory cooler on, it would require extra effort to hook it up incorrectly. The components come designed to be hooked up the proper way.

[LM7Yukon]

One of the lines from the aux. cooler should go to the cooler in the radiator.  If they put the GM accessory cooler on, it would require extra effort to hook it up incorrectly. The components come designed to be hooked up the proper way.

 

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Yes it does. 1 line goes from the aux cooler to the radiator. However, this does not make sense. Isn't the aux cooler supposed to be an independent cooler of the internal? what is air-to-oil mean?

[GM-Tech]

I already explained the reasons why.

[LM7Yukon]

I already explained the reasons why.

 

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No you didn't. You said that fluid goes through the internal cooler. I'm refering to the aux cooler which is connected to the inlet of the radiator, which your saying is correct. Thereore, if the aux is connected to the radiator, then how does the internal get used with the transmission?

[GM-Tech]

No you didn't.

 

From the second post in this thread...

 

"Even with the aux. cooler, trans fluid still goes throught the cooler built into the radiator. They don't want the trans to run too cold.

 

Radiator temp usually won't exceed 210-220, whereas under severe conditions (towing, etc.) the trans can easily exceed that. This is where the aux. cooler comes into play."

 

Read the first paragraph in particular.

[LM7Yukon]

No you didn't.

 

From the second post in this thread...

 

"Even with the aux. cooler, trans fluid still goes throught the cooler built into the radiator. They don't want the trans to run too cold.

 

Radiator temp usually won't exceed 210-220, whereas under severe conditions (towing, etc.) the trans can easily exceed that. This is where the aux. cooler comes into play."

 

Read the first paragraph in particular.

 

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But if the aux is connected to the line that connects the radiator to the transmission, then trans fluid is no longer going through the radiator, only the aux cooler.

[GM-Tech]

Okay, lets see if this works.

 

One line comes out of the trans. This connects to the lower part of the cooler in the radiator. The top line from the radiator cooler comes out and wraps around to enter the aux. cooler. The other line comes out of the aux. cooler and goes back to the trans.

 

Basically, the two coolers are in series. From the trans into one cooler, out of that cooler to the other cooler then back to the trans.

[LM7Yukon]

Okay, lets see if this works.

 

One line comes out of the trans.  This connects to the lower part of the cooler in the radiator.  The top line from the radiator cooler comes out and wraps around to enter the aux. cooler.  The other line comes out of the aux. cooler and goes back to the trans.

 

Basically, the two coolers are in series.  From the trans into one cooler, out of that cooler to the other cooler then back to the trans.

 

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Thanks... Now it makes sense.

[willfxp]

Even with the aux. cooler, trans fluid still goes throught the cooler built into the radiator.  They don't want the trans to run too cold.

 

Radiator temp usually won't exceed 210-220, whereas under severe conditions (towing, etc.) the trans can easily exceed that.  This is where the aux. cooler comes into play.

 

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Quick question.... "They don't want the trans to run too cold"? The transmission fluid l will warm up in the radiator?

 

 

BTW, LM7Yukon, that bold typing wasn't very nice.

[Mattt]

Any way to add a larger AUX cooler on a 2500HD? I have a thread going in the 2500HD section. My temps are normal, except when Im towing a heavy trailer, the temps creep up. See below.

 

http://www.gm-trucks.com/forums/index.php?...=0entry348633

[LM7Yukon]

BTW, LM7Yukon, that bold typing wasn't very nice.

 

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Didn't intend to be disrespectful. I used bold because the quote above my text was overwhelming.

[GM-Tech]

The transmission fluid l will warm up in the radiator?

 

Absolutely. The primary trans cooler is within the tank that contains the engine coolant, which warms up pretty quickly.