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Tranny coolers, which is better?

THRILLBILLY

THRILLBILLY

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Moving along in the list of upgrades in the build process, I'm wanting to install an external transmission cooler. I dont want to burn up the freshly rebuilt 700 with the heavy 44's I am running now. Since I have never installed one, I am wondering which type you guys would suggest. I pulled some random pictures off the internet just for visuals.

129_0905_21_zjeep_wrangler_hemitransmission_cooler.jpg


Or:

fccfa409.jpg


What are the pros and cons of both styles, and which one would cool better, install easier, etc... :dunno:
 
Thanks for the link! I figured stacked style would cool better. Didn't know if stacking them would restrict cooling the radiator any but with fans on both it should be fine.
 
Being in Fl., keeping engine parts cool is always a concern. I have seen some innovative rigs, .........And some really stupid ones.
Anything you put in front of your engine radiator is going to block some airflow. Most cars and trucks get away with it by over-sizing the radiator or increasing airflow with bigger fans or more fans.

So, if your truck runs cool now, you should be OK. If it runs on the warm side anyway, you might consider adding an electric fan, or increasing the thickness of your present radiator.

If all else fails, and you will be generating some serious heat in the transmission, I have seen the tranny cooler mounted off to the side with it's own electric fan. Sometimes horizontal blowing down.

The real question is, do you leave the cooling loop in the engine radiator in the circuit, and if so, does the fluid go through it first or last.............

There have been some good discussions here about that. Personally, I would leave it in. The heat transfer of the liquid is many times greater than air.
Trust me, I run a water-to-air heat pump in my farmhouse, and the condenser is about 4 loops of tubing about 2 feet across with water running through the outer jacket, and it replaces a big 4 ton outside unit.

People worry about the radiator heating up the transmission oil, but due to the efficiency of the water means the output temp is going to be pretty close to the radiator temp.
Which is hot, but not oil breakdown hot.
 
having a trans temp gauge is a good idea. Figuring it runs around 150-170, gets hot around 220, the engine radiator will effectively cool the trans fluid some. (figure coolant is 195* when exiting the engine, cooling the trans fluid downstream of the fan)

Like J said, using the internal cooler on the radiator is a good idea. Where you place it is up to you. Personally, I put the my air cooled radiator AFTER the internal cooler. I want the coolant to cool the trans fluid, then cool more with the air flow. It doesn't get "cold" enough here to worry about cold trans fluid.

Oh yeah. I got the biggest trans cooler BTO (BowTie Overdrives) sells.

12003.jpg
 
I think along with the tranny cooler a bigger core radiator will help as well. Never needed one with the 35's I was running. I do on the other hand have an electric fan and removed the mechanical fan from my truck. I was able to put the fan shroud back together when I did this as the body lift threw off alignment of the shroud. Cooling at that point was great. Right now I have a 16" fan off of a John Deere 9000 series tractor, which is one of 4 on those monsters. It pulls some serious air for sure, (standing about a foot in front it is pulling a piece of paper towards it.) haha, but here in Texas heat is a definte thing to tackle for sure, those triple digits are coming back...

I like the sound of leaving the internal in-line of the series. Getting two different sources for cooling seems like it will definitely help things out, but as with the unpredictable Texas weather it also can get below freezing. Cold trans fluid is also not good as well, am I right?

Now I've never dealt with trans coolers before so excuse my ignorance, and correct me if this is a stupid statement... Would running both sources of cooling cause below normal temperature in that case, or should I just shut up and listen to the pros? haha

What I have in mind for the whole setup is;
Inline B&M filter with temp sending unit hookup
AutoMeter Trans temp gauge
External cooler with electric fan
leaving inline cooler.

I should be running cool enough then I would hope...
 
if you live in a cooler climate, yes, running thru just an aux cooler can result in too much cooling...

see, the factory rad system only acts as a cooler in the sense that doesn't let the fluid get above engine temp.. but it also is a fluid heater, and brings the trans up to temp..

you want the fluid to get to at least 150 to cook off condensation.... 160 to 180 is prime operating range...

in the dead of winter here in Joysey, with just an aux cooler, my K5 trans was lucky to break 100.... bad juju...

and yes, stacked plate is what you want..
 
Last edited:
K85 Octane said:
having a trans temp gauge is a good idea. Figuring it runs around 150-170, gets hot around 220, the engine radiator will effectively cool the trans fluid some. (figure coolant is 195* when exiting the engine, cooling the trans fluid downstream of the fan)

Like J said, using the internal cooler on the radiator is a good idea. Where you place it is up to you. Personally, I put the my air cooled radiator AFTER the internal cooler. I want the coolant to cool the trans fluid, then cool more with the air flow. It doesn't get "cold" enough here to worry about cold trans fluid.

Oh yeah. I got the biggest trans cooler BTO (BowTie Overdrives) sells.

12003.jpg
Click to expand...

And of course there are differing opinions on how you mount the cooler...
some say to mount it so the fluid enters/exits from the top.
Others will say it should be horizontal so the fluid enters from the bottom, and exits the top.
As pictured here, the fluid enters/exits from the bottom, which some will argue doesn't allow the cooler to fill completely, and will be less effective.
I mounted mine this way, on the premise that GM engineers felt comfortable mounting them this way on all the trucks they build.
My 99 has both of its factory coolers mounted in this orientation.
 
76zimmer said:
And of course there are differing opinions on how you mount the cooler...
some say to mount it so the fluid enters/exits from the top.
Others will say it should be horizontal so the fluid enters from the bottom, and exits the top.
As pictured here, the fluid enters/exits from the bottom, which some will argue doesn't allow the cooler to fill completely, and will be less effective.
I mounted mine this way, on the premise that GM engineers felt comfortable mounting them this way on all the trucks they build.
My 99 has both of its factory coolers mounted in this orientation.
Click to expand...

Good point, thats something I never would have thought of! That's why I ask the pros! As far as entry points, I would guess that there is some sort of pressure on the lines anyways. If so, the fluid should fill it up if it has bottom entry/exit assuming there is enough pressure in the lines if any??
 
oh, it's pumping.... :haha:

the theory behind forcing the fluid to the top of a cooler is that it ensures no air pockets..
 
ryoken said:
oh, it's pumping.... :haha:

the theory behind forcing the fluid to the top of a cooler is that it ensures no air pockets..
Click to expand...

Sounds like a good theory to me. :waytogo:

Now for another crazy question, is there a way to bypass one or the other if the outside temp is cool enough that both wouldn't have to be used?
 
if you are worried that much about freezing temps, just do the air cooler first and finish with the radiator cooler. That way it enters the trans with a little heat. Only testing will tell, but you have several months before you need to worry about those temps, no? If that's not good enough, maybe some kind of slick homemade heat bag to slip over the air cooler could be used for that month. It's an idear
 
K85 Octane said:
if you are worried that much about freezing temps, just do the air cooler first and finish with the radiator cooler. That way it enters the trans with a little heat. Only testing will tell, but you have several months before you need to worry about those temps, no? If that's not good enough, maybe some kind of slick homemade heat bag to slip over the air cooler could be used for that month. It's an idear
Click to expand...

Im not extremely worried about it, just crossing t's and dotting i's. It is gonna be a really long several months before temperatures of that degree need to be addressed, I'm just trying to learn what options are there before spending my money! :thumb:
 
Through the radiator and into this, got it for free. I dropped weights on it and it's still holding up

P1000160.jpg
 
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