The GMC Envoy first went into production in 1998. Grouped into the midsize sports utility vehicle segment, the Envoy was completely redesigned in 2002. The Envoy uses the same platform as the Chevrolet TrailBlazer. Following the GMC recommended service schedule increases the longevity of every major Envoy component.
The 2009 GMC Envoy owner's manual recommends visually inspecting the fuel system for leaks every 25,000 miles. Inspect the exhaust system for loose or compromised components every 25,000 miles.
GMC recommends replacing the engine air-cleaner-filter and spark plugs at 50,000 engine-miles. Replace the air filter and spark plugs every 50,000 miles thereafter. Inspect the spark plug wires for damage at 100,000 miles if you drive an Envoy with a V-8 engine.
GMC suggests replacing the transfer case fluid at 50,000 engine-miles, and then again every 50,000 miles thereafter. The recommended service schedule calls for new, automatic transmission fluid at 100,000 engine-miles, and then again at 200,000 miles. If you occasionally drive in heavy traffic areas, rugged terrain or extreme weather environments, change the transmission fluid every 50,000 miles.
