1998 GMC Sonoma Owner's Manual - Page 362

Long Tripmighway Maintenance Schedule 97,500 Miles (162 500 km) Change engine oil and filter (or every 12 months, whichever occurs first). An Emission Control Service. 0 Lubricate chassis components (or every 12 months, whichever occurs first). (See footnote #.) 0 Check readfront axle fluid leveland add fluid as needed. Check constant velocity joints and axle seals for leaking. (See footnote **.) 0 Rotate tires. See "Tire Inspection and Rotation" in the Index for proper rotation pattern and additional information.(See footnote +.) DATE 1 Izi 100,000 Miles (166 000 km) 0 Inspect spark plug wires. An Emission Control Service. 0 Replace spark plugs. An Emission Control Service. 0 If you haven't used your vehicle under severe service conditions listed previously and, therefore, haven't changed your automatic transmission fluid, change both the fluidand filter. Manual transmission fluid doesn't require change. 0 4.3L Engine Only: Inspect Positive Crankcase Ventilation (PCV) valve. An Emission Control Service. DATE I