GM Service Manual Online
For 1990-2009 cars only

Fan Blade Clutch (RPO VO8 Heavy-Duty Cooling System)

    • Fan noise is normal if the noise occurs when the clutch engages for maximum cooling, or during the first few minutes after start-up.
    • If the clutch locks up, due to an internal failure, fan noise or an excessive roar will continuously occur under all high engine speeds (2500 RPM and up).
    • Replace the clutch if the fan blade cannot be rotated by hand, or if there is a rough, grating feel while turning the fan blade.
    • If maximum lateral movement at the fan blade tip exceeds 6 mm (0.236 in), replace the clutch.
    • Small fluid leaks, which may occur around the bearing area, do not require replacement. If the leakage appears excessive, do the following procedure:
        1. In order to ensure complete disengagement of the clutch, start with a cool engine.
        2. If the fan blade and the clutch freewheel with no drag (revolve more than 5 times when spun by hand), replace the clutch. Refer to Fan Clutch Replacement .