Cooling Fan Assembly

This procedure covers removal and replacement of the engine cooling fan assembly on the 5.9L Cummins diesel engine, including the fan clutch and fan blade.

Warnings

Tools required

Parts

• Cooling fan blade × 1 — Use OEM specification
• Fan clutch assembly × 1 — Use OEM specification
• Fan shroud mounting hardware × 1 — Replace if damaged

Fluids

• Ethylene glycol 50/50 (green conventional early, HOAT later) — 1 qt

Preparation

1. Ensure engine is completely cool to the touch
2. Disconnect negative battery cable to prevent accidental fan engagement
3. Remove engine cover if equipped
4. Place drain pan under radiator in case of coolant spillage

Procedure

1. 1

   Remove upper radiator shroud bolts
   Locate the upper radiator shroud mounting bolts along the top edge of the fan shroud. Remove all upper mounting bolts using a 10mm socket. Verify the number and location of upper shroud mounting bolts for your model year (the two-piece shroud on these trucks may use a different count than generic estimates).
2. 2

   Loosen lower shroud fasteners
   Locate the lower shroud tabs or bolts that secure the bottom of the shroud. On most models, these are clips or tabs that slide into the lower radiator support. Loosen or disengage these fasteners but do not fully remove the shroud yet.
3. 3

   Access fan clutch nut
   Position yourself to access the large fan clutch nut (verify size — commonly 36mm/1-1/4 inch, but confirm for your model year) at the center of the fan. The nut is located on the water pump/fan hub shaft. Verify you have adequate clearance to work - you may need to tilt the shroud slightly forward for access.
4. 4

   Remove fan clutch assembly
   Using the fan clutch holding tool or strap wrench to secure the water pump pulley, use the 36mm wrench to turn the fan clutch nut COUNTERCLOCKWISE to loosen. The fan clutch uses standard right-hand threads. Once loosened, unthread the fan clutch completely by hand. The fan blade is typically attached to the clutch and will come off as one assembly. Carefully guide the assembly out, being mindful not to strike the radiator with the fan blades.
   ⚠Fan clutch uses left-hand (reverse) threads. Turn CLOCKWISE to loosen.
5. 5

   Remove fan shroud
   With the fan assembly removed, lift the fan shroud up and away from the radiator. The shroud should now be free from all mounting points. Set aside in a safe location.
6. 6

   Inspect components
   Inspect the fan blades for cracks, chips, or damage. Check the fan clutch for excessive play, fluid leakage, or rough bearing operation. Inspect the shroud for cracks or broken mounting tabs. Replace any damaged components. Verify the water pump pulley is in good condition with no wobble or looseness.
7. 7

   Separate fan from clutch if replacing individually
   If replacing only the fan blade or only the clutch, remove the fan bolts securing the fan blade to the fan clutch hub (verify bolt count for your application). Keep hardware organized for reassembly.
   Torque spec

   Fan Bolts11 Nm (8 lb-ft)
8. 8

   Install fan shroud
   Position the fan shroud over the radiator, engaging the lower tabs or clips into the lower radiator support. Align the upper mounting holes with the radiator support but do not install bolts yet - the shroud will need to move for fan installation.
9. 9

   Assemble fan to clutch if separated
   If fan and clutch were separated, attach the fan blade to the fan clutch hub. Install the fan bolts and torque to the factory specification (verify value, typically around 18-21 lb-ft) in a criss-cross pattern to ensure even seating.
   Torque spec

   Fan Bolts11 Nm (8 lb-ft)
10. 10

    Install fan clutch assembly
    Carefully guide the fan and clutch assembly into position through the shroud opening, being careful not to damage radiator fins. Thread the fan clutch onto the water pump shaft by hand, turning CLOCKWISE (standard right-hand threads). Once seated, use the holding tool on the pulley and the 36mm wrench to tighten the fan clutch clockwise. Tighten securely to the factory-specified torque (verify against service manual, typically around 40-45 lb-ft) but do not over-torque.
    ⚠Left-hand threads - turn COUNTERCLOCKWISE to tighten.
11. 11

    Secure fan shroud
    With fan installed, ensure shroud is properly positioned around the fan with adequate clearance on all sides. Install and tighten all upper shroud mounting bolts. Verify lower tabs are fully engaged. Check that fan has approximately 1 inch clearance to shroud on all sides and can rotate freely without contact.
12. 12

    Reconnect battery and test
    Reconnect the negative battery cable. Start the engine and verify the fan operates smoothly without vibration or noise. Allow engine to reach operating temperature and verify fan clutch engages properly when engine is hot. Check coolant level and top off if needed.

Reassembly

1. Verify all shroud mounting bolts are tight and shroud is secure
2. Confirm fan has adequate clearance to shroud and radiator on all sides
3. Check coolant level after test run and top off as needed
4. Reinstall engine cover if equipped

Verification

• Start engine and verify no unusual fan noise or vibration
• Verify fan clutch engages and disengages properly as engine temperature changes
• Check for adequate clearance between fan and shroud during operation
• Confirm no coolant leaks around water pump area
• Verify fan spins freely when engine is cold and locks up when hot

Related trouble codes on this vehicle

Codes that commonly send this job to the bay — tap one for symptoms, causes, and diagnostic steps.

Chasing one of these codes and not sure which part is guilty? Ask a master mechanic about YOUR car →

More procedures for this vehicle