30 Row Stacked Plate Transmission Oil Cooler Kit 10AN

A 30 row stacked plate cooler with AN10 inlet and outlet, sold as a kit: the cooler core, two AN10 braided hoses (one 3.94 ft, one 3.28 ft), a 3/4 in mounting nut adapter, an M20 x 1.5 mounting nut adapter, an oil filter sandwich adapter and a hose clamp. Cooler oil capacity is about 0.35 L. The body is aluminum alloy with a black finish.

Stacked plate is the construction you want on an automatic. A tube-and-fin cooler runs the fluid through a single serpentine tube, so the fluid in the middle of the stream never touches the wall; a stacked plate core splits the flow across many thin plates and puts far more of the fluid against cooled metal per pass. That is why a plate cooler of a given face area drops more temperature than a tube-and-fin of the same size, and why it is the standard fix on trucks that tow.

Heat is what kills automatics. ATF starts oxidizing hard above roughly 240 F, and every 20 degrees over that cuts fluid life about in half; once the fluid darkens and loses its friction modifiers the clutches start slipping, the slip makes more heat, and the unit is on a one-way trip. An auxiliary cooler plumbed in line after the factory radiator cooler is the cheapest insurance there is on a truck that tows, hauls, or sits in traffic in summer.

Mounting notes: it has to sit somewhere with real airflow through the core, normally in front of the A/C condenser, and you need to measure the space before you order, because 30 rows is a tall core. Plumb it into the return line going back to the transmission, not the line leaving it, so the factory cooler does the bulk work and this one finishes the job. Use the supplied AN10 hoses, route them away from anything that moves or gets hot, then run the engine and check every fitting for weep before you load the truck.