OER Parts offers a wide selection of Automatic Trans & Components for your 2004 GMC Truck. OER Parts offers 2004 GMC Truck Complete Transmission, 2004 GMC Truck Cooler Lines, 2004 GMC Truck Dipsticks & Tubes, 2004 GMC Truck Flex Plate, 2004 GMC Truck Gaskets, Seals, Filters & Hardware 2004 GMC Truck Modulator Valves, 2004 GMC Truck Shift Knobs, 2004 GMC Truck Shift Linkage, 2004 GMC Truck Shifters - OE, 2004 GMC Truck Shifters - Performance, 2004 GMC Truck Torque Converter & Covers, 2004 GMC Truck Transmission Pans, and 2004 GMC Truck Vacuum Lines.