Get the Direct-Fit Transmission Coolers & Lines that will upgrade and fix the transmission cooling in your 2003-2010 Chevy/GMC Kodiak/TopKick 6.6L Duramax. The cooler lines are available in factory replacement or performance durable braided hoses with billet -AN fittings. The increase in fluid capacity and core volume will offer enhanced cooling efficiency with an aftermarket transmission cooler. Replace the problematic factory thermal bypass valve (if equipped) with a performance transmission cooler thermal bypass valve. There are many high-quality manufacturers accessible, including Dorman, BD-Power, Mishimoto, and others.