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SERIES 638 FRONT OIL SEAL

An oil seal is used on the front cover to retain the lubricating oil in the crankcase. The sealing lips of the front oil seal are held firmly, but not tightly, against the crankshaft thus preventing oil from escaping from the engine crankcase. ‪

The lips of the front oil seal bear against the crankshaft pulley/hub surface. See Figure 27757 . ‪

1.Front Oil Seal ‪

3.Front Cover ‪

2.Crankshaft ‪

Front Oil Seal Location

Replacement of Front Oil Seal

To determine if replacement of the front oil seal is necessary, perform the following procedure. See Figure 27956 . ‪

Flowchart for Replacement of Front Oil Seal

Removal of Front Oil Seal

If the front cover is installed, refer to section . ‪

If the front cover is removed, refer to section . ‪

Removal of Front Oil Seal (Front Cover Installed)

Remove the front oil seal as follows: ‪

To avoid personal injury when blow drying, wear adequate eye protection (safety glasses or face plate) and do not exceed 276 kPa (40 lb/in. 2 ) air pressure. ‪

  1. Preclean the front cover using clean fuel oil, and dry with compressed air.
  2. Remove the fan assembly. Refer to section .
  3. Remove the accessory drive belts. Refer to OEM guidelines.
  4. Remove the crankshaft vibration damper. Refer to section .
  5. Remove the crankshaft pulley. Refer to section .

    NOTICE:

    To avoid front cover and crankshaft end damage, use care when removing the front oil seal. ‪

  6. Remove the front oil seal from the front cover using a slide hammer. See Figure 27758 .

    1.Slide Hammer ‪

    3.Front Oil Seal ‪

    2.Crankshaft ‪

    4.Front Cover ‪

    Crankshaft Front Oil Seal Removal

Inspection of Front Cover Prior to New Front Oil Seal Installation

Inspect the front cover as follows: ‪

  1. Visually check the front cover for dents, cracks, and warpage.
    1. If the front cover has dents, cracks, or warpage, replace the front cover. Refer to section .
    2. If the front cover has no dents, cracks, or warpage, reuse the front cover. Refer to section .

Installation of Front Oil Seal (Front Cover Installed)

Install the front oil seal as follows: ‪

  1. Install new front oil seal using special tool VM-1015. See Figure 27764 .

    1.Front Oil Seal ‪

    3.Front Cover ‪

    2.Crankshaft ‪

    Front Oil Seal Installation

  2. Install crankshaft pulley. Refer to section .
  3. Install crankshaft vibration damper. Refer to section .
  4. Install accessory drive belts. Refer to OEM guidelines.
  5. Install fan assembly. Refer to section .
  6. Run the engine to verify repair.

Removal of Front Oil Seal (Front Cover Removed)

Remove the front oil seal as follows: ‪

To avoid personal injury when blow drying, wear adequate eye protection (safety glasses or face plate) and do not exceed 276 kPa (40 lb/in. 2 ) air pressure. ‪

  1. Preclean the front cover prior to removal using clean fuel oil, and dry with compressed air.
  2. Remove the fan assembly. Refer to section .
  3. Remove the accessory drive belts. Refer to OEM guidelines.
  4. Remove the crankshaft vibration damper. Refer to section .
  5. Remove the crankshaft pulley. Refer to section .

    NOTICE:

    To avoid front cover and crankshaft end damage, use care when removing the front oil seal. ‪

  6. Remove the front cover from the engine block. Refer to section and perform step through step

    NOTICE:

    Support the front cover evenly while driving out the oil seal to avoid front cover damage. ‪

  7. Remove the front oil seal from the front cover using a suitable punch and hammer from the backside of the cover driving the seal out. See Figure 27765 .

    1.Front Oil Seal ‪

    2.Front Cover ‪

    Front Oil Seal Removal

Inspection of Front Oil Seal (Front Cover Removed)

Inspect the front cover as follows: ‪

  1. Visually check the front cover for dents, cracks, and warpage.
    1. If the front cover has dents, cracks, or warpage, replace the front cover. Refer to section .
    2. If the front cover has no dents, cracks, or warpage, reuse the front cover. Refer to section .

Installation of Front Oil Seal (Front Cover Removed)

Install the front oil seal as follows: ‪

  1. Install new front oil seal using special tool VM-1015. See Figure 27766 .

    1.Front Oil Seal ‪

    2.Front Cover ‪

    Front Oil Seal Installation

  2. Install front cover. Refer to section .
  3. Install crankshaft pulley. Refer to section .
  4. Install crankshaft vibration damper. Refer to section .
  5. Install accessory drive belts. Refer to OEM guidelines.
  6. Install fan assembly. Refer to section .
  7. Run the engine to verify repair.