Mishimoto 03-09 Dodge Ram 5.9L/6.7L Cummins Transmission Cooler

Mishimoto has developed a direct-fit transmission cooler specifically for your 2003-2009 Dodge Ram 2500 or 3500 equipped with the 5.9L or 6.7L Cummins engine. Keeping your transmission cool is crucial, whether you're hauling heavy loads, working your truck hard, or just driving it daily. Excessive heat is the biggest enemy of any transmission, and this cooler is built to combat it effectively.

This transmission cooler features a stacked plate core, which offers a more durable and powerful cooling solution compared to stock. It boasts a massive 212-percent greater core volume and a 244-percent increase in fluid capacity, making it a significant improvement over the factory unit. Mishimoto also addressed a common failure point in stock coolers: the thermostat. When the stock thermostat fails, it often sticks closed, bypassing the cooler and sending hot fluid back to the transmission. Mishimoto's design makes the thermostat fully serviceable and easily bypassable. A port at the top allows for quick thermostat access for servicing, and replacement thermostats are available separately. For those in colder climates, the thermostat helps with faster warm-up times, while those in hotter climates can opt to bypass it using the included stainless-steel plug for constant cooling.

Installation is made easier thanks to the CNC-machined, stainless steel hose barb fittings. These allow you to cut off the stock quick-disconnect fittings and connect the supplied hose directly to the Mishimoto cooler, simplifying the process. This transmission cooler is backed by Mishimoto's Lifetime Warranty.