Flush the transmission in your 2001-2004 Chevy/GMC 6.6L LB7 Duramax with high-quality Transmission Fluid. Available in conventional and synthetic varieties, these transmission fluids offer longer service life by reducing damaging heat and wear. Using a quality fluid provides you with smooth gear changes and contains additives to prevent the formation of corrosion, rust, and foam. Royal Purple, Hot Shot's Secret, Lucas Oil, and Sun Coast Converters are just some of the manufactures XDP offers.