1999 GMC Sonoma Owner's Manual - Page 326

yellowblue Short Trip/City Scheduled Maintenance 48,000 Miles (80 000 km) (Continued) Check rear/front axle fluid level and add fluid as needed. Check constant velocity joints and axle seals for leaking. (See footnote **.) Rotate tires. See "Tire Inspection and Rotation" in the Index for proper rotation pattern and additional information. (See footnote +.) j j 50,000 Miles (83 000 km) j If you haven't used your vehicle under severe service conditions listed 51,000 Miles (85 000 km) previously and, therefore, haven't changed your automatic transmission fluid, change both the fluid and filter. Manual transmission fluid doesn't require change. DATE ACTUAL MILEAGE SERVICED BY: j Change engine oil and filter (or every 3 months, whichever occurs first). An Emission Control Service. j Lubricate chassis components (or every 3 months, whichever occurs first). (See footnote #.) j Check rear/front axle fluid level and add fluid as needed. Check constant velocity joints and axle seals for leaking. (See footnote **.) DATE ACTUAL MILEAGE SERVICED BY: 54,000 Miles (90 000 km) An Emission Control Service. j Change engine oil and filter (or every 3 months, whichever occurs first). 7-18 DATE ACTUAL MILEAGE SERVICED BY: