1997 GMC Safari Owner's Manual - Page 357

Long Trip/Highway Maintenance Schedule 30,000 Miles (50000 km) CI Change engine oil and filter (or every 12 months, whichever occurs first). An Emission Control Service. 0Change automatic transmission fluid and filter if the vehicle is mainly driven under one or more of these conditions: - In heavy city traffic where the outside temperature regularly reaches90°F (32°C) or higher. - In hilly or mountainous terrain. - When doing frequent trailer towing. - Uses such as found in taxi, police or delivery service. I f you do not use your vehicle under any of these conditions, change the fluid and filter every 30,000 miles (50 000 km). 0Lubricate chassis components (or every 12 months, whichever occurs first). (See footnote #.) 0Check readfront axle fluid level and add fluid as needed.Check constant velocity joints and axle seals for leaking. (See footnote **.) 0For Two-Wheel-Drive vehiclesonly: Clean and repack thefront wheel bearings (or at each brake relining, whichever occurs first).