1997 GMC Sonoma Owner's Manual - Page 355

I LongTripmighwayMaintenanceSchedule I 52,500 Miles (87 500 km) Cl Change engine oil and filter (or every 12 months, whichever occurs first). An Enzissiorz Control Service. C Check readfront axle fluid level and add l 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 7-45