External Auto Transmission Cooler

[blk92suprat]

I plan to add a Hayden tranny cooler in addition to the stock cooler inside the radiator.

For anyone who has this modification done, can you post picturs of how its routed with the internal radiator cooler.

 

[hvyman]

Forget the cooler in the radiator and just run the 2 hoses to big cooler in front of the radiator.

 

[Supra0089]

Forget the cooler in the radiator and just run the 2 hoses to big cooler in front of the radiator.

+1

If you want pics of it mounted under the driver headlight, I fit a 12x12 B&M cooler with a fan under mine...check my sig link

 

[Orion ZyGarian]

I disagree with this idea personally. The cooler in the radiator gets the tranny fluid up to temp quicker, and both balance each other's temps out. The best route imo is to put an external cooler before the radiator

 

[JDMMA70]

My setup

 

[Supra0089]

I disagree with this idea personally. The cooler in the radiator gets the tranny fluid up to temp quicker, and both balance each other's temps out. The best route imo is to put an external cooler before the radiator

In all seriousness, what are the benefits of having the fluid up to temp quicker? I've had my external installed for 3 years that completely bypasses the radiator cooler, and have not had any issues...

 

[IJ.]

I run external only, the Cooler lines are a low pressure/volume bypass, you can't overcool the Trans no matter how big a core you run.

I have a temp sensor in the Trans and it's temp lags behind the engine by about 5 minutes from a cold start.
(having said that the Diff is another 10 minutes behind that so you shouldn't hammer the car until everything is warm)

 

[Orion ZyGarian]

In all seriousness, what are the benefits of having the fluid up to temp quicker? I've had my external installed for 3 years that completely bypasses the radiator cooler, and have not had any issues...

...that you know of

The thing about engines and trannies are that they're meant to have oil at a certain temperature. It's possible to cool it too much, just as it's possible to overheat it. In most cases like with what you have, I highly doubt there would be much problem. It doesnt take too much time to get transmission fluid up to temperature if you dont leave it in neutral at stops. Think about it: when you're at a stop with an automatic, the engine and transmission are both doing what they can to get the car moving, but the brakes are holding it back. This will build up plenty of heat as the fluid coupling does the equivalent of a clutch slipping.

So basically it's a bigger issue with engines getting up to temp, especially since it's tough to overkill cooling on a transmission, but it is still possible.

I run external only, the Cooler lines are a low pressure/volume bypass, you can't overcool the Trans no matter how big a core you run.

I have a temp sensor in the Trans and it's temp lags behind the engine by about 5 minutes from a cold start.
(having said that the Diff is another 10 minutes behind that so you shouldn't hammer the car until everything is warm)

I imagine this is completely true as well, despite this unknown...."IJ." character giving the info

 

[blk92suprat]

+1

If you want pics of it mounted under the driver headlight, I fit a 12x12 B&M cooler with a fan under mine...check my sig link

Do you have it mounted with the face down?

 

[blk92suprat]

So the consensus is to ditch the stock cooler in the radiatior and run a dedicated external cooler. My Hayden is 11.6x11x.75. Sufficient for dedicated cooler?

Is it recommended to plug to OEM radiator tranny ports or puchase a new one that is designed for 5 spds(no internal cooler). I lke the PWR rad.

 

[Orion ZyGarian]

If you're 100% certain that you're not going to reuse them, you dont have to plug the ports on the radiator. You should IMO since you might need it later, who knows? If you order a radiator from somewhere like AutoZone or AdvanceAuto, you'll probably get an automatic radiator regardless, and all you have to do is not use the ports. I've had this happen with mine.

 

[Supra0089]

Mine is mounted with the fan underneath to suck are in from under the car as it's moving. My radiator is plugged. I had considered running oil through it one time to assist the oil cooler...but have been lazy. I hear people also run power steering through the radiator tranny cooler as well.

 

[blk92suprat]

Mine is mounted with the fan underneath to suck are in from under the car as it's moving. My radiator is plugged. I had considered running oil through it one time to assist the oil cooler...but have been lazy. I hear people also run power steering through the radiator tranny cooler as well.

Are you running OEM tranny or have you modified valve body and converter?

The OEM tranny cooler is full flow system unlike the engine oil cooler which is pressure based. Is this correct?

 

[IJ.]

Are you running OEM tranny or have you modified valve body and converter?

The OEM tranny cooler is full flow system unlike the engine oil cooler which is pressure based. Is this correct?

It's a bleed from the pump and very limited in pressure/flow, there's NO WAY you can overcool the Auto using that feed no matter how big a cooler is run....

 

[Orion ZyGarian]

It's a bleed from the pump and very limited in pressure/flow, there's NO WAY you can overcool the Auto using that feed no matter how big a cooler is run....

This guy knows what he's talking about (obviously). Automatics seem to be as thermally efficient as rotaries, if that. Think of an auto tranny similar to a manual tranny that is slipping all the time...on purpose.

 

[Nick M]

My Hayden is 11.6x11x.75. Sufficient for dedicated cooler?

That is a decent size. Do they rate it in BTUs?

 

[Nick M]

This guy knows what he's talking about (obviously). Automatics seem to be as thermally efficient as rotaries, if that. Think of an auto tranny similar to a manual tranny that is slipping all the time...on purpose.

The torque converter is slipping unless it is locked or in multiplication. The trans doesn't slip unless it is defective. And then, it is only the clutch pack, not the planetary gear set.

 

[Orion ZyGarian]

Newer ones are much better about it though. I believe the 8 speed auto in the new Lexus' will lock-up in 2nd gear!

Our older transmissions with old, burnt fluid are more likely to be slipping often. There's a very similar version of our transmission in many older Volvos like the 760 that didnt even have a lock-up converter..I think they called it the AW71 or something.

 

[Nick M]

The Aisin Warner was used in Jeep and Volvo off the top of my head.

 

[Orion ZyGarian]

Not sure if automatic Jeeps got the Aisin automatic trans (I dont watch that stuff as well as manuals), but the Aisin 5 speed is very similar to the R154. The Solstice for instance also got the AX5 I believe, which is also very similar to the R154. There's a writeup somewhere on here I believe that shows someone swapping it in, as it had newer triple cone synchros and stuff like that, but the shifter housing was wrong (not unlike the Soarer).