The number one transmission killer is heat Whether you are pulling heavy loads up long-steep grades, through hot-desert areas or just hauling more than you can handle, overheated oil reduces the life of your transmission and prone to leaving you broken down in the middle of nowhere. BDs Xtruded Transmission Oil Coolers uses the same high efficiency Micro Extruded bar technology that is in our air-to-air Charge Air Coolers, providing 22% more cooling over other designs. The 200 Micro Extruded passages provide a large surface area to transfer heat for external air flow cooling while turbulent oil flow design promotes a more complete cooling. Large 5/8-inch ports prevents inlet/outlet restriction and furnace brazed rails have been tested to 300psi of pressure. The thermostatically controlled 80-watt, 10-inch, 800 CFM electric fan offers ultimate automatic oil temperature control. This combination gives BDs Xtruded Transmission Oil Cooler a rating of 33,930 BTU/HR and in excess of 30,000 GVW! Xtruded Transmission Oil Cooler packages are available to accommodate 5/16, 3/8, 1/2 and 5/8 transmission cooler lines and come complete with all fittings, clamps, hoses, hardware and a Build-It-Yourself galvanized bracket kit for quicker and cleaner installation no wasting time fabricating brackets out of scrap metal. The pre-wired loomed harness with fuse and relay comes with OEM style sealed connectors to resist elements and give factory-like install look.