SERIES 638 CRANKSHAFT PULLEY

The crankshaft pulley is secured to the crankshaft with a retaining nut. The crankshaft pulley is positioned between the crankshaft vibration damper and the crankshaft. See Figure 27753 . ‪

1.Allen Head Bolt ‪	5.Crankshaft Pulley ‪
2.Lockwasher ‪	6.Front Cover ‪
3.Vibration Damper ‪	7.Damper Spacer ‪
4.Crankshaft Pulley Nut ‪	‪

Crankshaft Pulley Location

Note: The crankshaft pulley has a tapered fit to the crankshaft.

Two vee-type grooves in the crankshaft pulley provide drive belt seating surfaces. ‪

Repair or Replacement of Crankshaft Pulley

To determine if repair is possible or replacement is necessary, perform the following procedure. See Figure 27752 . ‪

Flowchart for Repair or Replacement of Crankshaft Pulley

Removal of Crankshaft Pulley

Remove the crankshaft pulley as follows: ‪

1. Remove the fan assembly. Refer to section .
2. Remove the crankshaft vibration damper. Refer to section .
3. Remove crankshaft pulley nut. See Figure 27753 .

   

   1.Allen Head Bolt ‪	5.Crankshaft Pulley ‪
   2.Lockwasher ‪	6.Front Cover ‪
   3.Vibration Damper ‪	7.Damper Spacer ‪
   4.Crankshaft Pulley Nut ‪	‪

   Crankshaft Pulley Removal

4. Remove front pulley, using special tool VM-1000-2, from the crankshaft. See Figure 27755 .

   

   1.Crankshaft Pulley ‪

   ‪

   Crankshaft Pulley Removal

   Note: The crankshaft pulley has a tapered fit to the crankshaft.

5. Remove crankshaft pulley seal. See Figure 27951 .

   

   1.Crankshaft Pulley ‪	3.Crankshaft ‪
   2.Crankshaft Pulley Seal ‪	‪

   Crankshaft Pulley Seal

Inspection of Crankshaft Pulley

Inspect the crankshaft pulley as follows: ‪

1. Visually check the crankshaft pulley for bent surfaces.
   1. If the crankshaft pulley has bent surfaces, install a new crankshaft pulley. Refer to section .
   2. If the crankshaft pulley has no bent surfaces, proceed with step of inspection.
2. Visually check the crankshaft pulley for broken or cracked edges.
   1. If the crankshaft pulley has broken or cracked edges, install a new crankshaft pulley. Refer to section .
   2. If the crankshaft pulley has no broken or cracked edges, proceed with step of inspection.
3. Visually check the crankshaft pulley for bent flanges on the drive belt seat grooves.
   1. If the crankshaft pulley has bent flanges on the drive belt seat grooves, install a new crankshaft pulley. Refer to section .
   2. If the crankshaft pulley has no bent flanges on the drive belt grooves, proceed with step of inspection.
4. Visually check the crankshaft pulley for roughness on the drive belt seat groove surface.
   1. If the crankshaft pulley has roughness on the drive belt seat groove surface, repair and reuse the component. Refer to section .
   2. If the crankshaft pulley has no roughness on the drive belt seat groove surface, proceed with step of inspection.
5. Visually check the crankshaft pulley for major roughness on the drive belt seat groove surface.
   1. If the crankshaft pulley has major roughness on the drive belt seat groove surface, install a new crankshaft pulley. Refer to section .
   2. If the crankshaft pulley has no major roughness on the drive belt seat groove surface, reuse the component. Refer to section .

Installation of Crankshaft Pulley

Install the crankshaft pulley as follows: ‪

1. Apply Loctite 510 to the crankshaft pulley retaining nut.
2. Install O-ring seal over crankshaft end. See Figure 27952 .

   

   1.Pulley Nut ‪	3.Crankshaft Pulley Seal ‪
   2.Crankshaft Pulley ‪	4.Crankshaft ‪

   Crankshaft Pulley Nut Installation

3. Slide crankshaft pulley on end of crankshaft. See Figure 27952 .

   Note: Pulley keyway must be in-line with crankshaft key during installation.

4. Install crankshaft pulley nut. Torque nut to 196 N m (145 lb ft). See Figure 27952 .
5. Install crankshaft vibration damper. Refer to section .
6. Install the fan assembly. Refer to section .
7. Run the engine to verify repair.

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