GMC Sierra 2500 HD2022 Owner's Manual page 395

394 Service and Maintenance
Additional Required Services
Maintenance Schedule Additional
Required Services - Normal
Rotate tires and perform Required Services. Check engine oil
level and oil life percentage. Change engine oil and filter,
if needed.
Check engine air filter life percentage and status. Change
engine air filter, if needed. (1)
Replace passenger compartment air filter. (2)
Replace spark plugs. Inspect spark plug wires and/or boots.
Change transfer case fluid, if equipped with 4WD. (3)
Drain and fill engine cooling system. (4)
Visually inspect accessory drive belts. (5)
Replace brake fluid. (6)
Replace windshield wiper blades. (7)
Replace hood gas struts and tailgate dampener. (8)
Replace air conditioning desiccant. (9)