RAM 1500 Truck 4WD V8-5.9L VIN Z (2002)
An air-to-oil transmission oil cooler is standard on all engine packages. The transmission oil cooler is mounted to the front of the radiator above the
power steering cooler (Fig. 2).
OPERATION
Transmission oil is routed through the cooler where heat is removed from the transmission oil before returning to the transmission. Vehicles equipped
with the 5.91- engine have an internal thermostat that controls fluid flow through the cooler. When the transmission fluid is cold (less than operating
temperature) the fluid is routed through the cooler bypass. when the transmission fluid reaches operating temperatures and above, the thermostat
closes off the bypass allowing fluid flow through the cooler. The thermostat MUST be removed from the cooler before the cooler can be flushed. The
thermostat is serviceable.
NOTE: Vehicles with the 3.7L/4.7L engines are not equipped with the oil cooler thermostat.