GM Genuine Parts Automatic Transmission Oil Coolers are designed, engineered, and tested to rigorous standards, and are backed by General Motors. These coolers are heat exchangers. They transfer heat to and from the vehicle transmission oil to the engine coolant or ambient air. This helps keep the transmission temperature within the designed operating range, which helps optimize transmission efficiency and longevity. GM Genuine Parts are the true OE parts installed during the production of or validated by General Motors for GM vehicles. Some GM Genuine Parts may have formerly appeared as ACDelco GM Original Equipment (OE).