Get the Direct-Fit Transmission Coolers & Lines that will upgrade and fix the transmission cooling in your 1998.5-2002 Dodge 5.9L 24V Cummins. The cooler lines are available in factory replacement or performance durable braided hoses with billet -AN fittings. Replace the problematic factory thermal bypass valve (if equipped) with a performance transmission cooler 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.