Derale 13504 Series 8000 Plate & Fin Transmission Oil Cooler

The Derale 13504 is a Series 8000 plate-and-fin auxiliary transmission oil cooler. It mounts inline ahead of the radiator and takes over the job the factory radiator cooler cannot keep up with once you start towing, hauling, or sitting in traffic on a hot day. Heat is what kills an automatic transmission — fluid that runs 40 to 60 degrees cooler can multiply the life of the clutches and the fluid itself.

Instead of a simple loop of tube, the plate-and-fin design stacks brazed cooling plates so the ATF spreads into thin layers and dumps heat fast. Embossed turbulators are pressed into each tube to keep the fluid churning against the plate walls rather than sliding straight through, which is where most of the extra cooling comes from. The core is furnace-brazed aluminum, so there are no crimped seams to weep, and extruded plastic guards protect the fins from road debris.

This is a universal fit cooler that plumbs into the transmission cooler lines — run the fluid through this cooler in series with (or in place of) the radiator cooler, then back to the transmission. The core measures roughly 11 in wide by 12 in tall by 7/8 in thick and weighs about 2.9 lb, so it tucks into most grille and lower-fascia openings without a custom bracket.

Good match for tow vehicles, trucks pulling trailers, performance builds, and any rig where the transmission temp gauge climbs under load. Derale part number 13504.