1999 GMC SIERRA 1500 PICKUP - Transmission, Transaxle Automatic Transmission, 4x2, 5.3L, Ext Cab, 60 Months Warranty. Free Shipping, 1 Month Return Policy. Used (Original Equipment Manufacturer). Transmission Tested and Run, covered by warranty. All Transmissions are Shipped as Complete Assemblies including: Transmission; Torque Converter (Automatic Transmissions Only); Oil Pan.