Recommendations for Cooling a C4 Transmission in a 1966 Ford Bronco Rock Crawler

Question:

I run a c4 in my 66 bronco rockcrawler. I am going to an aluminum radiator with no transmission cooler built into it. I have always ran an exterior cooler as well but feel I might need to add another or up grade. Any suggestions? I run 1 ton axles and 40 inch tires with both ends welded up and I wheel in some big stuff creating lots of heat. That is the reason for the radiator upgrade. The cooler I have is a crossflow about 6x8 inches. I do run an electric fan on it and another cooler the same size I run on the p/s. Thanks.

asked by: Laddle

Expert Reply:

It sounds to me like you will definitely want to upgrade your transmission cooler. Since you will not have a cooler that is being cooled by the fluid running through the radiator, I agree that you will need to upgrade or add a cooler to your system.

Heat Sink Coolers like the Dual-Pass Heat Sink Transmission Cooler, item # D13266, that you referenced are not nearly as efficient as a plate and fin cooler or a cooler with an electric fan added.

If you are running an electric fan with high CFM output on your new radiator, like the Dual High-Output, Electric Radiator Fan w/ Aluminum Shroud, item # D16825, I would suggest using the Derale Series 9000 Plate-Fin Transmission Cooler Kit, item # D13614, along with the exterior cooler you were already running.

If you are running a mechanical fan with your new radiator, I would then recommend the Derale 16-Pass Electra-Cool Remote Transmission Cooler Kit, item # D15900, that provides 650 CFM of airflow to the cooler, can be mounted in any location, and includes an inline 180 degree thermostat for automatic activation of the fan.

In my opinion, the Electra-Cool Kit seems to be the best recommendation for your situation. When rock crawling you will be traveling at low speeds and putting strain on the engine and transmission which will create heat. Providing additional air flow can only help your vehicle handle the extreme situations you will encounter. One thing to keep in mind is that heat is the enemy of your transmission and you cannot cool transmission fluid too much, so going bigger with this system cannot hurt.

The above suggestions are based on the information you provided, but you should consider having a qualified technician look over your setup to determine if any other factors would play into cooling your transmission, such as engine size.