Specifications

Preventive Maintenance Engine Maintenance
Medium Duty
(R05/09) Y53-6008A – 173 –
Engine Fan
Thermatic (Clutch) — Type Fan
WARNING! Do not work on the fan with the
engine running. The engine fan can engage at
any time without warning. Anyone near the fan
when it turns on could be seriously injured.
Before turning on the ignition, be sure that no
one is near the fan.
To Check the Fan:
• Check the fan assembly mounting bolts for tightness.
Inspect the blades for damage.
• Check the clutch operation by starting the engine when it
is cold. Then idle it at about 800 RPM. Listen for air
leaks.
• Check that the fan is not working while the engine is
warming. When the clutch engages, note the reading on
the vehicle's panel—mounted coolant temperature
gauge. If the fan clutch engages at low engine tempera-
ture or cycles on and off more frequently than it should
(receives “false signals”), have the problem corrected at
an Authorized Service Center.
Fan Drive and Blade
Fan Blade Clearance: Around the fan shroud, the recom-
mended distance is 1 in. (25 mm) from front edge of any fan
blade-to-radiator side member. Minimum clearance is 3/4 in.
(19 mm).
• Rear edge of any blade must be no closer than 3/8 in.
(9 mm) to the nearest engine component. If this cannot
be obtained, the fan spacer or fan is not correct.