2003 GMC Sonoma Owner's Manual - Page 376

0 Change automatic transmission fluid and filter if the vehicle is mainly driven under one or more of these conditions: - In heavy city traffic where the outside temperature regularly reaches 90°F (32°C) or higher. - In hilly or mountainous terrain. - When doing frequent trailer towing. - Uses such as found in taxi, police or delivery service. If you do not use your vehicle under anyof these conditions, change the fluid and filter every 50,000 miles (83 000 km). 21,000 Miles (35 000 km) 0 Change engine oil and filter (or every 3 months, whichever occurs first). An Emission Control Service. 0 Lubricate chassis components (or every 3 months, whichever occurs first). (See footnote #.) 0 Check readfront axle fluid level and add fluid as needed. Check constant velocity joints and axle seals for leaking. (See footnote **-) 24,000 Miles (40000 km) 0 Change engine oil and filter (or every 3 months, whichever occurs first). An Emission Control Service. 0 Lubricate chassis components (or every 3 months, whichever occurs first). (See footnote #-) 0 Check readfront axle fluid level and add fluid as needed. Check constant velocity joints and axle seals for leaking. (See footnote **.) 0 Rotate tires. See Tire Inspection and Rotation on page 5-66 for proper rotation pattern and additional information. (See footnote +.) 18,000 Miles (30000 km) 0 Change engine oil and filter (or every 3 months, whichever occurs first). An Emission Control Service. 0 Lubricate chassis components (or every 3 months, whichever occurs first). (See footnote #.) 0 Check readfront axle fluid level and add fluid as needed. Check constant velocity joints and axle seals for leaking. (See footnote **.) 0 Rotate tires. See Tire Inspection and Rotation on page 5-66 for proper rotation pattern and additional information. (See footnote +,) 6-9