GMC 2001 Denali Owner's Manual page 366

Scheduled Maintenance
50,000 Miles (83 000 km)
j
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 any of these conditions, change the
fluid and filter at 100,000 miles (166 000 km).
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
SERVICED BY:
MILEAGE
DATE
ACTUAL
SERVICED BY:
MILEAGE
7-11