2002 GMC Envoy Owner's Manual - Page 390

Scheduled Maintenance 50,000 Miles (83 000 km) 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 any of these conditions, change the fluid and filter at 100,000 miles (166 000 km). j Automatic Transfer Case Only: Change transfer case fluid. j Change automatic transmission fluid and filter if the vehicle is mainly driven DATE ACTUAL MILEAGE SERVICED BY: 52,500 Miles (87 500 km) j Check rear/front axle fluid level and add fluid as needed. Check constant velocity joints and axle seals for leaking. j Rotate tires. See "Tire Inspection and Rotation" in the Index for proper rotation pattern and additional information. (See footnote +.) DATE ACTUAL MILEAGE SERVICED BY: 7-11