When changing your transmission fluid and filter note the color of the fluid. If the fluid is brownish in color and smells like burnt toast, the vehicle could be experiencing transmission overheating. Every 20°F decrease in fluid temperature can double the life of the fluid and transmission components. Protect your vehicle's transmission - install a Hayden transmission oil cooler. The addition of a Hayden cooler can lower your transmissions temperature by up to 60°F, three times the amount required to double the life of your transmission.