Installing Tranny cooler

mcreyaufmiller · January 21, 2007

I lost the instructions, (shame on me ). However, I do understand the idea, but what I need to know is: does the cooler go inline before or after the radaitor cooler?

Rolandd · January 21, 2007

A good question, and several schools of thought. If you are towing and/or you live in a warm climate, usually you put the cooler after the radiator (from a tranny oil flow perspective) to give additional cooling. However, if you live in a very cold environment and are installing the cooler because you plow you may want to put the cooler before the radiator so that if the tranny fluid is overcooled it can be reheated by the radiator to maintain operating temperature. The argument is that overcooled oil may slow the responses of the hydraulic actuators for the bands and clutches causing slippage.

dewfpo · January 21, 2007

The fastory installation in our trucks is from the trans to the radiator to the external cooler back to the trans. But as Roland states...... their are different ways it can be done.

DEWFPO

mcreyaufmiller · January 21, 2007

Thanks, I am just adding it as an accessory for the new tranny and also for towing my new camper.

C & A s Dad · January 21, 2007

I cannot speak for extremely cold climates but I can tell you that I have installed at least 6 or 7 trans coolers and have never seen any include any instrcutions to install the cooler with the fluid running through it first and then through the radiator. I am sure those who live in cold climates have experience with this but it would seem the mfg of the cooler would make some mention of this in the instructions.

Not disputing anyone, just raising the question.

fossil · January 22, 2007

You install the cooler after the rad irregardless of how hot the or cold the climate you operate in is. If you're concerned about over cooling and having the fluid congeal in very cold weather, consider installing an " H " fitting in the lines just before the aux cooler. That way if the fluid in the aux cooler congeals, the fluid will bypass through the "H" fitting and you wont fry your tranny.

C & A s Dad · January 22, 2007

I will add that a good "Stacked Plate" cooler is designed to let cooler thicker fluid pass through "un-cooled" and as the fluid heats up and thins out it begins to actually pass through the cooling plates. Please be sure you are buying a stacked plate designed cooler. They are far more efficient and less restrictive than a Tube and Fin cooler.

There are many opinions on "over cooling" trans fluid and I am sure in extremely cold climates this could happen. However where I live and with the research that I did, it simply cannot happen. I have heard some people say they must reach 180 degrees min to evaporate the moisture and impurities. This is true with an Internal Combustion engine that has produces a lot of by products as it runs. However, with a transmission, it simply is not true according to what I could find.

I spoke with a trans remanufacturing company and a local franchised rebuilder and they both told me the same thing. As long as it is reaching 120 degrees or so, you will have not issues. At this temp the fluid is hot and "fluid" enough to do what it was designed to do. A trans is sealed so there really are no impurties or moisture to "boil off" as it is in an engine. The rebuilder showed me a Chev El Camino with over 250K on the original trans. He has had a massive Staked Plate cooler on it since new and the trans temps have never run higher than 125 to 135.

If someone has info that will prove this wrong, please pass it along to us.

az'03Silverado · January 23, 2007

If you're really concerned about overcooling in a bitter-cold climate, just do like the truckers do and block the airflow a little. One of those magnetic vent covers (those big sheets of magnet material used to block a vent in a house) might work or a piece of canvas or something.

ridgekid · January 23, 2007

In my opinion it should go to the tranny cooler first, then throught the radiator.

Here's why- Your tranny fluid will be hot, if you pre-cool it BEFORE the radiator your not adding that heat to a radiator thats already removing engine heat. If your in a cold climate, it will warm the oil back up before going back to the tranmission. The tranny oil will run at a more constant temperture. Less friction that way.

EDIT: Then again I could be wrong. I found this at Summit. It shows how to install a cooler in Series:

http://static.summitracing.com/global/imag...s/sum-g4960.pdf

Rolandd · January 24, 2007

I stand corrected (or sit, as I usually type while sitting). Installing the cooler before the radiator was a trick that I remember being told about from a tranny builder I worked with in the early eighties. He was from Wisconsin or Minisota or Michigan or someplace like that and I remember him indicating that he never used that trick while living in New England because it was not cold enough to warrent it.

C & A s Dad · January 24, 2007

Rob, you are entitled to your opinion but I can tell you that all factory coolers route the fluid through the cooler in the radiator first and then through the aux cooler. Also, all of the instructions that I have ever seen included with a aux cooler also do the same.

I cannot speak for all vehicles but the cooler that is inside the radiator on most vehicles is simply a piece of metal line that loops down into coolant in the radiator tank and back out again. I can promise you that there is not much heat transfer going on with that set up and certainly not enough to add any significant heat to the engine coolant.

A properly operating cooling system is going to control the engine heat. What you are concerned about here is the extreme heat build up in the trans fluid due to heavy towing. A good stacked plate aux cooler properly installed will take care of this concern.

Again, you are certainly entitled to your opinion.