The XDP X-TRA Cool Direct-Fit Transmission Oil Cooler XD309 is a direct upgrade for the factory transmission oil cooler in your 2001-2005 FOR GM 6.6L Duramax LB7/LLY. XDP’s XTRA-Cool Transmission Oil Coolers are made using techniques borrowed from the HD and semi-truck industry to provide you with the ultimate in strength and durability.
