Fan Clutch
Fan Clutch Test1. Spin the fan blade by hand. A light resistance should be felt, but the fan will not spin freely if spun by hand. If there is no resistance or very high resistance, the fan speed must be checked as follows:
2. A slight fan "wobble" is allowable by design, unless the wobble causes noticeable vibrations to the vehicle.
Fan Clutch Test-Minimum Speed Requirement
WARNING: To avoid the possibility of personal injury or damage to the vehicle, do not operate the engine until the fan blade has been first examined for possible cracks and separation.
1. Use a suitable marker to mark the coolant pump pulley and one of the fan blade retaining bolts.
2. Connect a tachometer to the engine.
3. Install a throttle adjusting tool.
4. Connect a digital photoelectric tachometer.
5. Start the engine and run it at approximately 1,500 rpm (for at least two minutes) until the normal operating temperature has been achieved. The A/C must be off.
6. Operate the digital photoelectric tachometer at 3,000 rpm and aim it at the coolant pump pulley. Adjust the engine speed until the light flash and the coolant pump pulley mark are synchronized.
7. Aim the digital photoelectric tachometer at the fan blade bolts. Adjust the strobe light until the light flash is synchronized with the marked fan blade bolt (the fan blade appears to stand still).
8. The fan blade speed must not be greater than 1,500 rpm at 3,000 coolant pump rpm.
9. Turn the engine off.
10. NOTE: A new fan blade must not be installed unless physical damage is observed. An undamaged blade can be reused with a new fan clutch.
If the fan blade speed was greater than 1,500 rpm, install a new fan clutch.