1997 GMC Suburban Owner's Manual - Page 384

I Short Trip/Cits Maintenance Schedule -- Gasoline Engines I 99,000 Miles (145 000 km) 0Change engine oil and filter (or every 3 months, whichever occurs first). An Emission Control Service. 100,000 Miles (144 000 km) 0Inspect spark plug wires. An Emission Control Service. 0Replace spark plugs. An Emission Control Service. 0Lubricate chassis components (or every 3 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 **.) 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 O F (32 C) or higher. O DATE ACTUAL MILEAGE SERVICED BY: I 7-28