Ensuring your GM 6.6L transmission maintains optimal temperature keeps it performing its best during heavy towing, off-roading, and daily driving. High-performance activities generate excess heat, which can strain your transmission and lead to premature wear and tear. For enhanced performance and long-term reliability, our selection of transmission coolers and thermal bypasses is the ideal solution for your transmission. Whether you opt for upgraded coolers for enhanced cooling efficiency or thermal bypasses to keep fluid temperatures cool, we have everything you need to keep your transmission running smoothly and reliably. Check out our selection of Transmission pans, filters, fluidfor additional cooling performance! GM Duramax Fitments: 2001, 2002, 2003, 2004 GM 6.6L Duramax.Submodel Fitments: WT, Custom, LT, LTZ, High Country, 1LT, 2LT, Pro, SLE, SLT, AT4, Denali.Some exceptions apply, please see individual product pages for specific fitments.