Operation CHARM: Car repair manuals for everyone.

Transmission Cooling

Automatic Transmission

CAUTION: Do not attempt to backflush and clean the oil-to-air fluid cooler. The OTA fluid cooler must be replaced as part of a transmission overhaul, or transmission damage may result.

All vehicles with automatic transmissions are equipped with an Oil-To-Air(OTA) fluid cooler. Vehicles equipped with the 5.4L- engine are also equipped with a cooler that is integral to the radiator. In operation, transmission fluid travels from the transmission to the oil-to-air fluid cooler then back to the transmission. The oil-to-air fluid cooler transfers heat from the transmission fluid to outside air.
On vehicles equipped with the 5AL engine, transmission fluid travels from the transmission to the integral cooler in the radiator then to the OTA fluid and back to the transmission.
The integral fluid cooler transfers heat from the transmission fluid to the engine coolant.





Transmission Cooler 5.4L





Oil-To-Air Fluid Cooler-5.4L and 6.8L





Oil-To-Air Cooler-7.3L Diesel