SERIES 638 FRONT COVER

The front cover forms a sealed compartment for the engine gear train. See Figure 27767 . ‪

1.Crankshaft Pulley ‪

2.Front Cover ‪

Front Cover Location

The front cover has a raised area that is used to indicate Top-Dead-Center of the No. 1 piston for fuel injector pump timing. See Figure 27767 . The front cover also serves as a retainer for the front oil seal. ‪

Replacement of Front Cover

To determine if repair of the front cover is necessary, perform the following procedure. See Figure 24156 . ‪

Flowchart for Repair or Replacement of Front Cover

Removal of Front Cover

Remove the front cover 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 .
6. Remove 13 Torx head bolts securing the front cover to the engine block.
7. Remove one Torx head bolt securing the weep hose bracket to the engine block. See Figure 27769 .

   

   Weep Hose Bracket Removal

   NOTICE: ‪
   When removing the front cover, use care not to bend or warp the front cover sealing surfaces or oil leakage will occur during engine operation. ‪

8. Remove the front cover using a stiff blade scraper to cut seal.

Cleaning of Front Cover

Clean the front cover 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. Remove any dirt or debris from the front cover using clean fuel oil and dry with compressed air.
2. Remove sealing compound from front cover surface.

Inspection of Front Cover

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 Cover

Install the front cover as follows: ‪

1. Apply a uniform bead of Dow Corning 7091 silicone sealant to the front cover surface.
2. Install the front cover with 14 Torx head bolts. See Figure 27770 for torque values.

   

   Front Cover Torque Values

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

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