2004 GMC Sierra 1500 Pickup Owner's Manual - Page 542

Additional Required Services The following services should be performed at the first maintenance service (I or II) after the indicated miles (kilometers) shown for each item. Additional Required Services Service Allison transmission only: Replace external control-main filter. See footnote (l). Inspect fuel system for damage or leaks. Inspect exhaust system for loose or damaged components. Vehicles without a filter restriction indicator: Replace engine air cleaner filter. See Engine Air Cleaner/Filter on page 5-23. An Emission Control Service. 6-speed manual transmission only: Change clutch fluid. See footnote (n). 25,000 (41 500) 50,000 (83 000) 75,000 (125 000) 100,000 (166 000) 125,000 (207 500) 150,000 (240 000) • • • • • • • • • • • • • • • • • • • • • • • • 6-6