Derale 13504 Series 8000 Plate & Fin Transmission Cooler

The Derale 13504 is a Series 8000 plate and fin auxiliary transmission cooler that mounts in front of the radiator or condenser and pulls heat out of the ATF before it goes back into the case. It is a universal cooler, not a vehicle-specific part, so it works on any automatic that runs cooler lines: 4L60E, 4L65E, 4L80E, 700R4, TH350, TH400, A518/46RE, 47RE, E4OD, 4R100, AOD and 4R70W among others. Core is furnace-brazed aluminum with embossed turbulators pressed into each tube, which keeps the fluid tumbling instead of sliding through in a smooth column, so more of it actually touches the tube wall and gives up its heat.

Heat is what kills automatics. ATF is happy around 175 to 200 degrees F; every 20 degrees over that roughly halves fluid life, and by the time you are seeing 250 the clutch friction material and the seals are cooking. Trucks that tow, plow, or sit in traffic with a converter slipping are the usual candidates. If you are chasing burnt fluid, a shudder that shows up after 30 minutes of driving, or you are putting a freshly rebuilt unit back in a truck that already ate one, an auxiliary cooler is cheap insurance and belongs on the job.

Installation: plumb it in series on the cooler return line coming back from the radiator to the transmission, so the factory radiator cooler does the bulk work and this one finishes the job. Mount it in clean airflow ahead of the A/C condenser with the supplied hardware, keep the hose runs short with no kinks, double-clamp the connections, then top off and check level at operating temperature. Kit dimensions are 11 in wide by 12 in tall by 7/8 in deep and the core comes with extruded plastic fin guards to keep road debris from folding the fins.