Derale 14201 Standard Depth Transmission Cooling Pan for GM TH-400Derale's TH400 Transmission Cooling Pan #14201 uses air passing beneath the vehicle and redirects it to help lower transmission oil temperatures. With brazed, turbulator equipped airway tubes passing through the lower section of the transmission pan for more efficient cooling, each is individually pressure tested to ensure a leak free pan. We've included a much stronger magnetic drain plug and rubber steel reusable washer, in addition to a 1 8" NPT