Series 638 – Section 1.17 Flywheel Housing

Section 1.17
Flywheel Housing

The flywheel housing is a one-piece casting mounted against the rear of the cylinder block. It provides a cover for the flywheel, positions the rear main bearing carrier assembly, seals the rear of the engine, and serves as a support for the cranking motor and transmission. See Figure "Flywheel Assembly" .‪

1.Flange Head Bolt‪	7.Thrust Washer‪
2.Allen Head Screw‪	8.Nut‪
3.Spring Washer‪	9.Spacer Plate Seal Ring‪
4.Camshaft Seal Ring‪	10.Spacer Plate‪
5.Rear Bearing Housing Assembly‪	11.Flywheel‪
6.Cylinder Block‪	‪

Figure 1. Flywheel Assembly

Section 1.17.1
Repair or Replacement of Flywheel Housing

To determine if repair or replacement of the flywheel housing is necessary, perform the following procedure. See Figure "Repair or Replacement of Flywheel Housing Flowchart" .‪

Figure 2. Repair or Replacement of Flywheel Housing Flowchart

Section 1.17.2
Removal of Flywheel Housing

Remove the flywheel housing as follows:‪

1. Remove the flywheel. Refer to "1.16.2 Removal of the Flywheel" .
2. Remove the spacer plate. See Figure "Flywheel Housing Part Location" .
   

   1.Bolt‪	7.Thrust Washer‪
   2.Allen Head Screw‪	8.Nut‪
   3.Spring Washer‪	9.Spacer Plate Seal Ring‪
   4.Camshaft Seal Ring‪	10.Spacer Plate‪
   5.Rear Bearing Housing Assembly‪	11.Flywheel‪
   6.Cylinder Block‪	‪

   Figure 3. Flywheel Housing Part Location

3. Remove ten bolts. See Figure "Flywheel Housing Part Location" .
4. Remove six rear carrier nuts. See Figure "Flywheel Housing Part Location" .
5. Remove flywheel housing from the cylinder block. See Figure "Flywheel Housing Part Location" .
6. Remove camshaft O-ring seal. See Figure "Flywheel Housing Part Location" .

Section 1.17.2.1
Inspection of Flywheel Housing

Inspect the flywheel housing as follows:‪

1. Measure the flywheel housing for flatness.
   1. If the flywheel housing is not flat, replace the component. Refer to "1.17.3 Installation of Flywheel Housing" .
   2. If the flywheel housing is flat, proceed with step 2 of inspection.
2. Visually check the flywheel housing for cracks.
   1. If the flywheel housing is cracked, replace the component. Refer to "1.17.3 Installation of Flywheel Housing" .
   2. If the flywheel housing is not cracked, proceed with step 3 of inspection.
3. Visually check the flywheel housing machined surface for roughness.
   1. If the flywheel housing machined surface is rough, repair the sealing surface using emery cloth. Refer to "1.17.3 Installation of Flywheel Housing" .
   2. If the flywheel housing machined surface is not rough, reuse the component.

Section 1.17.3
Installation of Flywheel Housing

Install the flywheel housing as follows:‪

1. Install a new camshaft O-ring seal to the flywheel housing. See Figure "Flywheel Housing Part Location" .
   

   1.Bolt‪	7.Thrust Washer‪
   2.Allen Head Screw‪	8.Nut‪
   3.Spring Washer‪	9.Spacer Plate Seal Ring‪
   4.Camshaft Seal Ring‪	10.Spacer Plate‪
   5.Rear Bearing Housing Assembly‪	11.Flywheel‪
   6.Cylinder Block‪	‪

   Figure 4. Flywheel Housing Part Location

2. Install the flywheel housing to the cylinder block using 10 bolts. Torque the bolts to 47 N · m (35 lb · ft). See Figure "Flywheel Housing Part Location" .
3. Install rear crankshaft carrier nuts. Torque nuts to 24 N · m (18 lb · ft). See Figure "Flywheel Housing Part Location" .
4. Install new spacer plate O-ring seal.
5. Install the spacer plate using an Allen head screw. Torque screw to 3 N · m (24 lb · in.). See Figure "Flywheel Housing Part Location" .
6. Install the flywheel. Refer to "1.16.3 Installation of Flywheel" .
7. Run the engine to verify repair.