Vehicles manufactured after 1975 will have transmission coolers built into the car’s radiator. It is designed to cool down transmission oil during operation. The emergence of it helps to extend the life of the transmission and increase the fluid’s service intervals.
Stress on the transmission builds heat
Under normal operating temperatures, the transmission oil will flow properly and allow adequate friction. When the temperatures get too high, the oil can break down, or lose it’\s ability to lubricate some parts while hydraulically separating others. By installing a transmission cooler, these temperatures are kept as low as possible by forcing the fluid through a hose to the front of the vehicle, then through a series of coils and fins to cool it down. It returns to the transmission to complete the cycle. The pressure of the transmission in operation keeps the fluid in motion, so the cooler will not operate when the vehicle is turned off.