1997 GMC Sonoma Owner's Manual - Page 358

I Long Trip/Highway Maintenance Schedule 75,000 Miles (125 000 km) 0Change engine oil and filter (or every 12 months, whichever occurs first). An Emission Control Service. 0Check readfront axle fluid level and add fluid as needed. Check constant velocity joints and axle seals for leaking. (See footnote **.) 0Rotate tires. See "Tire Inspection and Rotation'' in the Index for proper rotation pattern and additional information. (See footnote +.) 0Lubricate chassis components (or every 12 months, whichever occurs first). (See footnote #.) DATE ACTUAL MILEAGE SERVICED B Y 7-48