1997 GMC Sonoma Owner's Manual - Page 316

Maintenance Schedule I Long TripMighway Definition Follow this maintenance schedule only if none of the conditions from the Short Trip/City Maintenance Schedule is true. Do not use this schedule if the vehicle is used for trailer towing, driven in a dusty area orused off paved roads. Use the Short Trip/City schedule for these conditions. Driving a vehicle with a fully warmed engine under highway conditions causes engine oil to break down slower. Every 7,500 Miles (12500 km): Engine Oil and Filter Change (or every 12 months, whichever occurs first). Chassis Lubrication (or every 12 months, whichever occurs first). Drive Axle Service. Tire Rotation. Every 30,000 Miles (50000 km): Fuel Filter Replacement. Air Cleaner Filter Replacement. Front Wheel Bearing Repack (2WD only) (or at each brake relining, whichever occurs first). Every 50,000 Miles (83 000 km): Automatic Transmission Service (severeconditions only). Every 60,000 Miles (100 000 km): Engine Accessory Drive Belt Inspection. Fuel Tank, Cap and Lines Inspection. Every 100,000 Miles (166 000 km): Spark Plug Wire Inspection. Spark Plug Replacement. Positive Crankcase Ventilation (PCV) Valve Inspection. Every 150,000 Miles (240 000 km): Cooling System Service (orevery 60 months, whichever occurs first). These intervals only surnnzarize maintenance services. Be sure tofollow tlw complete maintenance schedule on the.following pages. 7-6