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03-09 Dodge 5.9L Cummins Mishimoto Transmission Cooler

Keep the transmission cool in your 2003-2009 Dodge 5.9L/6.7L Cummins with the Mishimoto MMTC-RAM-03SL Transmission Cooler. Whether your truck is a tow rig, daily driver, or built for street performance, the Mishimoto Direct-Fit Transmission Cooler gives you greater cooling efficiency. with a 212% increase in core volume, and a 244% increased in fluid capacity, this transmission cooler drastically increases cooling capacity. 


Not only is the Mishimoto Transmission Cooler larger, and more efficient, the design also makes it more durable. If the thermostat in your factory transmission cooler fails it fails in a closed position. This bypasses the cooler and returns hot fluid to the transmission. Mishimoto fixed this issue and has designed this Transmission Cooler for easy servicing. The built-in port on the top of the cooler provides easy access to the thermostat so you don't need to replace the entire cooler if the thermostat fails. Mishimoto also includes a stainless steel bypass plug to bypass the thermostat for those in warm climates. 


The Mishimoto Transmission Cooler comes ready to install with CNC-machined stainless steel barbed hose fittings so you can remove the factory quick-disconnect lines, and mate this cooler to the stock soft-lines to the Mishimoto Cooler. Includes cooler, lines, thermostat, thermostat bypass, barb fittings and worm gear clamps.



Direct-Fit Replacement

212% Increase In Core Volume 

244% Increase In Fluid Capacity 

Stacked Plate Design for Tough & Reliable Cooling

Mishimoto Lifetime Warranty



Material: 6061 Aluminum

Core Height: 10.94"

Rows: 48

Core Thickness: 0.87"

Core Length: 26" 

Fitting Size: 3/4"-16 SAE ORB 

Increased Capacity: 0.88 Quarts


Application Notes: 

This kit requires cutting of the stock trans cooler lines. 

Included stainless steel hose barb fittings splice soft lines on cooler to stock lines on truck. 

To install this transmission cooler with AN hoses, you must purchase qty (2) of the Mishimoto -80RB To -8AN Aluminum Fitting MMFT-8ORB-8BK (sold separately, see related items below). 



Part Number: MMTC-RAM-03SL

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Tags: 03 , 09 , Dodge , 5.9 , L , Cummins , Mishimoto , Transmission , Cooler