2004 CHEVROLET IMPALA - Transmission, Transaxle Automatic Transmission, 3.8L, Supercharger Opt, 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.