Get the Direct-Fit Transmission Coolers & Lines that will upgrade and fix the transmission cooling in your 2004.5-2007 Dodge 5.9L Cummins. Get performance braided hoses with billet -AN fittings or factory replacement cooler lines for your vehicle. Performance transmission cooler thermal bypass valves are available for some applications that will replace the problematic factory thermal bypass valve. Most aftermarket transmission cooler give you greater cooling efficiency by an increase in core volume and fluid capacity. Mishimoto, Dorman, BD-Power, and more top-notch manufacturers are available.