
- Fits all 2003–2009 Dodge Ram 5.9L & 6.7L Cummins*
- 212% increase in core volume
- 244% increase in fluid capacity
- Includes fully serviceable thermostat for fast warm-up in cold climates and thermostat bypass for constant cooling in hot climates
- Stacked-plate design for tough and reliable cooling
- Eliminates corrosion-prone quick-disconnect fittings
- Available -8ORB to -8AN adapters allow the use of AN transmission fluid lines. (2 required)
- Patent #D912,701
- Mishimoto Lifetime Warranty

There’s no greater enemy for a transmission than heat. Whether your 2003–2009 Dodge Ram 5.9L/6.7L Cummins is a dedicated tow vehicle, hardworking fleet truck, or a daily driver with a liking for the dragstrip, you need to ensure that your transmission runs cool. Luckily, Mishimoto has developed a direct-fit transmission cooler to do just that. Our 2003–2009 Dodge Ram 5.9L/6.7L Cummins transmission cooler utilizes a stacked-plate core for durable and powerful cooling. With a massive 212% greater core volume and 244% increase in fluid capacity, this trans cooler is a huge improvement over the stock 2003–2009 Dodge Ram 5.9L / 6.7L Cummins transmission cooler.
The Mishimoto transmission cooler is not only larger than the stock cooler but more reliable too. When the stock cooler’s thermostat fails, it fails closed, bypassing the cooler and returning hot fluid to the transmission. Mishimoto has solved this common issue by making the thermostat in our 2003–2009 Dodge Ram Cummins transmission cooler fully serviceable and easily bypassed for constant cooling. A port located at the top of the cooler provides easy access to the thermostat for servicing in just a few min[...]
- Fits all 2003–2009 Dodge Ram 5.9L & 6.7L Cummins*
- 212% increase in core volume
- 244% increase in fluid capacity
- Includes fully serviceable thermostat for fast warm-up in cold climates and thermostat bypass for constant cooling in hot climates
- Stacked-plate design for tough and reliable cooling
- Eliminates corrosion-prone quick-disconnect fittings
- Available -8ORB to -8AN adapters allow the use of AN transmission fluid lines. (2 required)
- Patent #D912,701
- Mishimoto Lifetime Warranty