Separate Trans Cooler Or Run Through Radiator??

[Cliff Ramsdell]

Another thing to think about is cooler line size. The stock cooler lines were 5/16” and these were fine until the late 80’s when the A500 (42RH) and the A518 (46RH) came out and we started having failures in the overdrive. I believe the switch over to 3/8” lines was done in either ‘90 or ‘91 and this increased the volume of flow back to the transmission.

On the early pre OD units return lube was used to lube the gear sets on the output shaft. I don’t recall the return lube circuit on the OD units but we have one on the bench now and I’ll research that more.

All factory coolers mounted away from the radiator but in the air path. Some of the Dodge Ram trucks had a remote cooler under the truck bed right behind the cab area and a fan kit with a switch allowed it to run separately to help further cooling on the Diesel trucks.

Cliff Ramsdell

 

[ckessel]

I elected to keep my cooler separate from the radiator. The trans, along with one each for the engine and p/s, are mounted to the stone shield behind the front bumper and between the rails. I'm going to enlarge the opening, which is behind where the license plate normally mounts, by using opening pieces I cut out of two core bumpers for that reason. This way I'll be getting air directly across them and separate from the radiator. I made up my own core support so the radiator core is fully exposed to air and it will be sealed off to the support and hood so less airflow escapes and helps to maximize airflow through the engine compartment to assist getting heat out of the area. I may make up some belly/splash pans if I feel there needs to be more control of the flow through the area. Part of my reasoning to do this is following how the newer vehicles focus airflow through the bay to maximize cooling of hot components that do not have a cooling system of their own other than just airflow.

 

[451 Big Block]

I separate the cooling so as to not put any more heat under the hood. Like 493 Mike, I have a Derale trans radiator with a fan, but mine is located under the back seat. Works great. Use braided stainless flexible lines.

 

[440 Charger]

Now the Charger is running and about ready to drive, Im on the fence as to which way to keep the trans cool. I'd like to keep from adding heat under the hood as much as possible. Running an aluminum 3 core, shroud with a 7 blade clutch. Probably fine but, like I said. Anyone have any good/bad experiences with the long, narrow rail mounted coolers. Drive train is all stock and have a cheesy Summit chrome, slightly finned trans pan with a drain plug that may not do a damn thing..., ($30 and dont leak!). Appreciate any input, thanks!
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Bigger is always better with coolers. From what I have seen plate cooler the transmissions I have do built in thermostats.

 

[JG71B]

Went this route for now. Ill figure a better plan than going under the core support down the road.

 

[66Satellite47]

That should work fine. Good space away from the radiator. You may want to double clamp those hoses if the lines don't have the bulge on the end.

 

[JG71B]

That should work fine. Good space away from the radiator. You may want to double clamp those hoses if the lines don't have the bulge on the end.

Yup, I have everything double clamped if there is no flare

 

[33 IMP]

I have a simple question.
If, as i understand it, the cooler you run your auto trans, (within reason) the better/longer lasting....
And if, my auxiliary cooler can keep my trans temp around 165/175°......
Why would i want to run the transfluid thru a radiator with 195/215° coolant in it?

 

[Mike67]

I went through a fan powered Derale cooler it sits a couple of inches from the radiator behind my bumper. Cruising it should get air and when in traffic the fan will provide adequate cooling. I also have a deep pan that adds a couple of extra quarts to boot

 

[JG71B]

I have a simple question.
If, as i understand it, the cooler you run your auto trans, (within reason) the better/longer lasting....
And if, my auxiliary cooler can keep my trans temp around 165/175°......
Why would i want to run the transfluid thru a radiator with 195/215° coolant in it?

How I try and make sense of it is, what my laser shows at least, mine runs about 180-185 now that all is good. I'll assume the trans runs just as hot because of the heat it produces itself and cuz it's bolted to the motor absorbing that heat as well. It maintains normal engine temp thru the rad. and then gets a little extra cooling after the fact with the smaller cooler and "strategically" placed metal lines, (hopefully it works in my favor this way like I'm picturing it in my head!). So I would think or at least hope it takes it down to 160- 180. Ill have to bust out the laser again on that

 

[747mopar]

this is my thinking - say your trans fluid is 180 or so degrees coming out of the trans, you route it to a heat exchanger exposed to ambient temps of ~85-90 degrees. This is cooled off noticeably, then you introduce it to the rad trans cooler that has the fluid temp of say 200 degrees as the cooling medium. You just warmed up the trans fluid going back to the trans and negated the trans cooler you installed. That's why I think the trans fluid should go to the radiator cooler first and then to the trans cooler exposed to ambient air to further cool it down, before returning it to the transmission. Just my 2 cents worth.

I just installed a Hayden oil cooler and the instructions said just that, radiator then cooler.