Add another measure of protection and increase fluid flow to the transmission cooler. Increase cooling capacity with this easy-to-install billet aluminum PPE Transmission Fluid Thermal Bypass Valve for the GM 10L80 10-Speed transmission. The OEM part has restrictive internal passages. When the OEM valve fails in the closed position, transmission fluid doesn't reach your cooler. This can be caused by mechanical failure or debris. The result of stock valve failure can cause the transmission to overheat dangerously. Without properly cooled transmission fluid, the demands of towing and rigorous stop-and-go driving conditions shorten the life of transmission components. The PPE Bypass Valve eliminates the extremely restrictive mechanical factory valve, maximizing fluid flow to and from the transmission cooler. For further protection, a Neodymium magnet-equipped service plug with O-ring seal has been added. The removable plug traps ferrous debris and can be accessed to remove particles from the system. The factory bypass valve does not have this feature. OEM part number 84518145