2010 GMC Acadia Owner's Manual - Page 416

11-6 . Service and Maintenance First Engine Oil Change After Every 160 000 km/100,000 Miles . All‐wheel drive only: Transfer case fluid change (severe service) for vehicles mainly driven when frequently towing a trailer, or used for taxi, police, or delivery service. During any maintenance, if a power washer is used to clean mud and dirt from the underbody, care should be taken to not directly spray the transfer case output seals. High pressure water can overcome the seals and contaminate the transfer case fluid. Contaminated fluid will decrease the life of the transfer case and should be replaced. First Engine Oil Change After Every 240 000 km/150,000 Miles . Automatic transmission fluid change (normal service). See Automatic Transmission Fluid on page 10‑11. Spark plug replacement and spark plug wires inspection. An Emission Control Service. All‐wheel drive only: Transfer case fluid change (normal service). During any maintenance, if a power washer is used to clean mud and dirt from the underbody, care should be taken to not directly spray the transfer case output seals. High pressure water can overcome the seals and contaminate the transfer case fluid. Contaminated fluid will decrease the life of the transfer case and should be replaced. . . Engine cooling system drain, flush, and refill, cooling system and cap pressure check, and cleaning of outside of radiator and air conditioning condenser (or every 5 years, whichever occurs first). See Cooling System on page 10‑14. An Emission Control Service. Engine accessory drive belt inspection for fraying, excessive cracks, or obvious damage and replacement, if needed. An Emission Control Service. .