TRU-COOL 40000 gvw - Transmission Cooler Location - Sahara Desert Trip

My name is Óscar, my and my 2006 Hummer H3 3.5 luxury auto enjoyed driving together so many desert trips to sahara, and recently the Spain National Rally TT.

I usually have trans temp of 170ºf daily driving, that is correct. But in the Rally and sahara desert dunes (sometimes driving in 4High Lock and others in 4Low Lock) the trans temp climbs so much, to the 210-220ºf mark.

Just for that, and for the off road use that i do with the hummer, i reinforced certain elements:
-Outfitter design steering bushing rack kit and front differential bushing kit (this made a huge difference)
-Moog u-joints in the rear propeller shaft.
-Alpha CV-Joints (the stock cv replacement now, for all years)

Now, because the trans temp, I am going to install these trans cooler:


I am from Spain, here, the climate is usually hot (40 ºC in summer), and I usually go to Sahara desert once or two a year. So I am going to install the trans cooler without bypass valve (winter temperature of 10-15 ºC).

I see in a previous post of ''Citiboy'', that he install this transmission cooler in a Hummer H3 v8 Alpha, here are the pics from his install:



Here is my question: I want to put two small electric fans in front of the transmission cooler (sahara temp of 40-45 ºC), so I am a bit lost about location of the transmission cooler in relation to engine radiator (I dont want to cut air flow to engine radiator (smaller cut possible)).
So here are a draw that I made about the location, there are two location possible, upper or lower...I think because of the two small fans in trans cooler I can install it lower, because the fan will compensate the lower airflow from the exterior, this solution allows the engine radiator to have better air flow throw the front chrome grille.

Here is the draw:


What do you guys think? I am going to put two buttons for each fan inside the cabin.

Another thing to say is that I buy a Volant powercore CAI (155356) is listed for the chevrolet colorado and gmc canyon, but I think (seeing the part number of the air box and elements (the same than Hummer h3)) that is going to be well.
Thanks you so much. Great forum, and great Hummer Product.

1. The trans cooler 40K is too cool for your application. I ran 30K on my V8 and when I go offroad in the desert in 50 celsius summer the trans temps didnt go above 85 celsius. On road I get 70 celsius in summer

2. I run a new stall converter at 3200K (much more heat than stock) so I upgraded to 40K. Its great but on the highway it gets too cold (45 celsius). Weather here in the winter is usually 15 celsius in the day. I will add a bypass to get trans temp 60 celsius at the least.

3.The only way to run the fans is behind the radiator support bracket. The H3 alpha from SA came with 2 fans (11" and 9") put infront of the condenser. There is a 7 cm gap between the condenser and the radiator support.

Your setup should be: condesner - fan (s) - trans cooler.



If you try to run the fans infront of the trans cooler, the radiator support bracket will come in the middle and this will force you to use two small fans (approx 8" fans)

Btw, You can instal one spal 16" pusher fan that will fit between the condenser and the radiator support bracket.

Below is a picture I borrowed from the site (shows the support bracket - vertical and the body - horizontal).

Check this post

http://www.hummer4x4offroad.com/forum/showthread.php?p=138643

amrg is right on target.

Thanks you so much for fast and great respond!
If I understand well, I have to install the bypass valve (hope that is reliable), for winter and onroad temps. And the correct setup is like amrg said: Condenser - Medium size fan or dual small fan - transmission cooler.

Then the location of the transmission cooler will be upper, am i correct? And a very important thing is: there are two types of fan in my knowledge, one will suck air (like the mechanical stock fan) and other will push air. What type should I get? (with the setup that amrg said)

Thanks you so much again!

You need a pusher fan infront of the condenser.
The trans cooler doesnt block airflow because there are alot of gaps around it for air to pass (at idle).

If you want the biggest fan, get a spal 16" pusher fan.
This will barely fit

http://www.universalpartsinc.com/shopping/productDetails.aspx?i=750015&c=10502

It is the biggest fan you can fit with minor modification. The vertical support will need to have shims installed behind it to give you 0.5 cm extra space to clear the fan motor.

If you want, get a sensor in the radiator hose that when reaches lets say 99 celsius switches the fan on and when it goes down to 91 off.

Guerreo, soy un canario viviendo en USA. Tengo un Alpha y vivo en el sur donde hace temperaturas de más de 40. A mi también se me calentaba mucha la transmisión. Yo hice dos cosas. Cambie el radiador a uno de doble celda sin refrigeración para la transmisión. Después le puse un radiador dedicado solo para la transmisión como el que tu pillaste. Esto evita el intercambio de calor. Esto también evita la contaminación del líquido de transmisión cuando falla el radiador doble de fabrica. Después convertí la ventilación falsa del capo a una funcional. Esta combinación hizo que la temperatura se mantuviera estable sin más calentamientos.

Wow thanks you so much Amrg, great responds, now I am certainly in the right direction. Thanks you so much too Recon!

For Recon in Spanish: (Gracias campeon! Se hace difícil hablar por aquí en Inglés pero el foro es buenísimo y la actitud asi como el conocimiento de lo mejorcito, por cierto, vi tu preparación paso por paso del Alpha, increible, sinceramente. Disfrutalo muchísimo, es lo que trato de hacer yo! )

Now I have another question that dont let me sleep...if I put the transmission cooler with the fittings pointing down, an air bubble can occur! Is that correct? What is the correct orientation? Or maybe the correct procedure to bleed the system of air.

Just for you (curiosity), I learned a lot time ago, when replacing the coolant from the radiator, that the correct procedure of filling it is to fill first the engine (via top hose in the radiator (you have to unplug it) slowly, so you can hear a lot of air bubbles, then when its filled, you can plug the hose and fill the radiator to top. With this procedure, I notice a noticeable difference in engine coolant temperatures in a few H3 that I fix here in Spain.

Thanks you so much Again! Here two pictures for you. Sahara desert, 2009 (long time ago..)

Guerrero. Este foro es claramente el mejor para Hummer. Mucha gente agradable que sabe muchísimo. Yo he estado en todos los foros y me quedo con este. Los otros hay mucho enterado y demasiado drama de telenovela venezolana.





Esta es mi otra joya hecha completamente en Tenerife y homologado para circular.



Esta es mi colección en Tenerife menos en Cherokee (XJ) que lo vendí.

Guerrero said:

Now I have another question that dont let me sleep...if I put the transmission cooler with the fittings pointing down, an air bubble can occur! Is that correct? What is the correct orientation? Or maybe the correct procedure to bleed the system of air.

Click to expand...

You can have the fittings pointing up, or if pointing to the side, the inlet should be at the bottom and the exit at the top. You should not have the fittings both pointing down for the reason you stated.

Thanks you so much Alrock!

Yes, I thought the same, but in the tru-cool website, in the FAQ question , they say that you can install it up, down or side. Whatever you want without problem... :/
I dont know what to think about it now.

Recon: Increibles! Por lo que veo te gusta ese color! jeje asi se diferencia tu personalidad, sigue asi. Yo ire posteando mas por aqui, tengo muchas fotos increibles.

Thanks you so much again.

Guerrero said:

Thanks you so much Alrock!

Yes, I thought the same, but in the tru-cool website, in the FAQ question , they say that you can install it up, down or side. Whatever you want without problem... :/
I dont know what to think about it now.

Recon: Increibles! Por lo que veo te gusta ese color! jeje asi se diferencia tu personalidad, sigue asi. Yo ire posteando mas por aqui, tengo muchas fotos increibles.

Thanks you so much again.

Click to expand...

I too had this question when I installed mine, Alrock is the expert, so I took his advice and mounted it side ways....BUT I didn't change it side ways until about 1500 miles ago and didnt have any over heating issues.