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SERIES 638 CRANKSHAFT

The crankshaft is a one-piece forging, heat-treated to ensure strength and durability. See Figure 28428 . ‪

1.Crankshaft Drive Gear ‪

6.Main Bearing Carrier Assembly ‪

2.Crankshaft ‪

7.Carrier Dowel ‪

3.Keys ‪

8.Spring Washer ‪

4.Main Bearing ‪

9.Allen Head Screw ‪

5.Piston Jet Valve ‪

Crankshaft and Related Parts

The main connecting rod bearing journal surfaces and fillets are hardened. ‪

Complete static and dynamic balance of the crankshaft has been achieved by counterweights incorporated in the crankshaft. ‪

The crankshaft end play is controlled by the thrust washers in the rear main bearing carrier assembly. ‪

Full pressure lubrication to all connecting rods is provided by drilled passages within the crankshaft See Figure 28443 . ‪

Crankshaft Lubricating Oil Holes

Repair or Replacement of Crankshaft

To determine if repair or replacement of the crankshaft is necessary, perform the following procedure. See Figure 28429 . ‪

Flowchart for Repair or Replacement of Crankshaft

Removal of Crankshaft

Remove the crankshaft as follows: ‪

  1. Remove flywheel. Refer to section .
  2. Remove flywheel housing. Refer to section .
  3. Remove oil pump. Refer to section .
  4. Remove vacuum pump. Refer to section .
  5. Remove connecting rod and piston assembly. Refer to section .
  6. Remove the six crankshaft carrier adaptors. See Figure 28453 .

    Note: Mark each crankshaft carrier adaptor for installation.

    1.Crankshaft Carrier Adaptor No. 1 ‪

    4.Crankshaft Carrier Adaptor No. 4 ‪

    2.Crankshaft Carrier Adaptor No. 2 ‪

    5.Crankshaft Carrier Adaptor No. 5 ‪

    3.Crankshaft Carrier Adaptor No. 3 ‪

    6.Crankshaft Carrier Adaptor No. 6 ‪

    Crankshaft Carrier Adaptor Location

    NOTICE:

    To avoid crankshaft gear damage, place VM 1004 over the front of the crankshaft gear to prevent crankshaft gear damage during crankshaft removal. ‪

  7. Position the engine with the crankshaft facing up.
  8. Place crankshaft removal sleeve VM 1004, over front crankshaft gear. See Figure 28448 .

    1.Crankshaft Gear ‪

    2.Crankshaft Removal Sleeve ‪

    Crankshaft Removal Sleeve

  9. Pull the crankshaft outward until the crankshaft carriers are out of their respective bores.
  10. Disassemble crankshaft carriers by removing two Allen head retaining bolts and spring washers. See Figure 28428 .

    1.Timing Drive Gear ‪

    6.Bearing Assembly ‪

    2.Crankshaft ‪

    7.Center Bearing Dowel ‪

    3.Keys ‪

    8.Spring Washer ‪

    4.Main Bearing ‪

    9.Allen Head Screw ‪

    5.Piston Jet Valve ‪

    Crankshaft Carrier Parts Location

  11. Remove carriers from crankshaft.
  12. Reassemble and number each carrier to ensure correct installation.
  13. Remove the crankshaft from the cylinder block.
Cleaning of Crankshaft

Clean the crankshaft as follows: ‪

  1. Remove any dirt or debris from the crankshaft using clean fuel oil.

    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. ‪

  2. Clear the crankshaft oil passages with compressed air.
  3. Dry the crankshaft with compressed air.
Inspection of Crankshaft

Inspect the crankshaft as follows: ‪

  1. Visually check the crankshaft for nicks, scratches, cracks or seizure marks.
    1. If the crankshaft has any nicks, scratches, cracks or seizure marks, replace the component. Refer to section .
    2. If the crankshaft has no signs of any nicks, scratches, cracks or seizure marks, proceed with step of inspection.
  2. Visually check the crankshaft rear and front end mating surfaces and threads for scratched, deformed or worn surfaces.
    1. If the crankshaft rear and front end mating surfaces and threads are scratched, deformed, or worn, replace the component. Refer to section .
    2. If the crankshaft rear and front end mating surfaces and threads are not scratched, deformed, or worn, proceed with step of inspection.
  3. Visually check the timing gear teeth for wear or damage.
    1. If the timing gear teeth are worn or damaged, replace the component. Refer to section .
    2. If the timing gear teeth are not worn or damaged, proceed with step of inspection.
  4. Measure the crankshaft journals and pins in two perpendicular directions to check for wear and out-of-round. See Figure 28416 and see Figure 28417 .
    1. If the crankshaft journal and pin wear exceeds 0.10 mm (0.0039 in.), replace the component. Refer to section .
    2. If the crankshaft journal and pin wear is within 0.10 mm (0.0039 in.), proceed with step of inspection.
    3. Measuring for Perpendicularity (First Direction)

      Measuring for Perpendicularity (Second Direction)

  5. Magnaflux check to detect surface cracks on the crankshaft
    1. If cracks are detected on the crankshaft, replace the component. Refer to section .
    2. If cracks are not detected on the crankshaft, proceed with step of inspection.
  6. Measure the diameter of the crankshaft journal H" and compare measured results with specification values listed in Table . See Figure 28415 .
    1. If the crankshaft journal diameter is not within specifications (listed in Table ), replace the component. Refer to section .
    2. If the crankshaft journal diameter is within specifications (listed in Table ), proceed with step of inspection.
    3. Measuring Connecting Rod Big End Journal

      Bearing Size

      Diameter of Connecting Rod Big End Journal (H)

      Diameter of Connecting Rod Bearing (L)

      Standard ‪

      53.995-53.940 mm (2.1257-2.1236 in.) ‪

      53.977-54.016 mm (2.1250-2.1266 in.) ‪

      0.125 mm (0.0049 in.) US ‪

      53.830-53.815 mm (2.1192-2.1186 in.) ‪

      53.852-53.891 mm (2.1201-2.1216 in.) ‪

      0.250 mm (0.0098 in.) US ‪

      53.705-53.690 mm (2.1143-2.1137 in.) ‪

      53.766-53.777 mm (2.1167-2.1172 in.) ‪

      0.500 mm (0.0196 in.) US ‪

      53.445-53.440 mm (2.1041-2.1039 in.) ‪

      53.477-53.516 mm (2.1053-2.1069 in.) ‪

      Crankshaft Journal Specifications

      Note: Journal bearing clearance: 0.030-0.064 mm (0.0011-0.0025 in.)

      Note: Minimum admissible diameter: 53.440 mm (2.1039 in.)

  7. Measure the diameter of the central main journal C" and compare measured results with specification values listed in Table . See Figure 28421 .
    1. If the central main journal diameter is not within specifications (listed in Table ), replace the component. Refer to section .
    2. If the central main journal diameter is within specifications (listed in Table ), proceed with step of inspection.
    3. Crankshaft Central Main Journal

      Bearing Size

      Diameter of Central Main Journal C"

      Diameter of Central Bearing D"

      Standard ‪

      63.020-63.005 mm (2.4810-2.4805 in.) ‪

      63.050-63.093 mm (2.4822-2.4839 in.) ‪

      0.125 mm (0.0049 in.) US ‪

      62.895-62.880mm (2.4761-2.4755 in.) ‪

      62.925-62.968mm (2.4773 in.) ‪

      0.250 mm (0.0098 in.) US ‪

      62.770-62.775 mm (2.4712-2.4714 in.) ‪

      62.800-62.843 mm (2.4724-2.4741 in.) ‪

      0.500 mm (0.0196 in.) US ‪

      62.520-62.505 mm (2.4614-2.4608 in.) ‪

      62.550-62.593 mm (2.4625-2.4642 in.) ‪

      Specifications for Diameters of Central C" and D" Main Journal

      Note: Bearing Length H" : 27.75-28.00 mm (1.0925-1.1024 in.)

  8. Measure the diameter of the rear main journal F" and compare measured results with specification values listed in Table . See Figure 28422 .
    1. If the rear main journal diameter is not within specifications (listed in Table ), replace the component. Refer to section .
    2. If the rear main journal diameter is within specifications (listed in Table ), proceed with step of inspection.
    3. Crankshaft Rear Main Journal

      Bearing Size

      Diameter of Rear Main Journal

      Standard ‪

      69.985-70.000 mm (2.7553-2.7559 in.) ‪

      0.125 mm (0.0049 in.) US ‪

      69.860-69.875mm (2.7503-2.7509 in.) ‪

      0.250 mm (0.0098 in.) US ‪

      69.735-69.750 mm (2.7454-2.7461 in.) ‪

      0.500 mm (0.0196 in.) US ‪

      69.485-69.500 mm (2.7356-2.7362 in.) ‪

      Specifications for Diameter of Rear Main Journal
  9. Measure the diameter of the front main journal A" and the diameter of the front bearing B" and compare measured results with specification values listed in Table . See Figure 28420 .
    1. If the rear main journal diameter is not within specifications (listed in Table ), replace the component. Refer to section .
    2. If the rear main journal diameter is within specifications (listed in Table ), reuse the component. Refer to section .
    3. Crankshaft Central Main Journal

      Bearing Size

      Diameter of Central Main Journal A"

      Diameter of Central Bearing B"

      Standard ‪

      62.985-63.000 mm (2.4797-2.4803 in.) ‪

      63.088-63.043 mm (2.4838-2.4820 in.) ‪

      0.125 mm (0.0049 in.) US ‪

      62.860-62.875 mm (2.4747-2.4754 in.) ‪

      62.963-62.918mm (2.4788-2.4771 in.) ‪

      0.250 mm (0.0098 in.) US ‪

      62.735-62.750 mm (2.4698-2.4705 in.) ‪

      62.838-62.793 mm (2.4739-2.4722 in.) ‪

      0.500 mm (0.0196 in.) US ‪

      62.485-62.500 mm (2.4600-2.4606 in.) ‪

      62.588-62.543 mm (2.4641-2.4623 in.) ‪

      Specifications for Front Main Journal A" and Front Bearing B"

      Note: Bearing Length E" : 27.75-28.00 mm (1.0925-1.1024 in.)

Installation of Crankshaft

Install the crankshaft as follows: ‪

NOTICE:

To avoid crankshaft damage, carefully guide the crankshaft through the cylinder block to avoid damaging the crankshaft journal ends. ‪

  1. Install the crankshaft gear, if removed.
  2. Using VM 1004, install the crankshaft into the cylinder block placing the crankshaft journals outside of their respective cylinder bores to allow installation of the carriers, using VM 1004.

    Note: Engine should be positioned so that the crankshaft is facing up during installation.

  3. Install carriers to the crankshaft as numbered during removal. Torque to 44-45 N m (32-33 lb ft).

    NOTICE:

    To avoid engine damage, ensure that the main bearing carriers (lower half) holes are aligned correctly with the center of the cylinder block. See Figure 28458 . ‪

  4. Slide the assembled crankshaft into the cylinder block. See Figure 28458 .

    1.Carrier Oil Hole Alignment Location ‪

    Main Bearing Carrier Oil Hole Alignment

  5. Install six crankshaft carrier adaptors. See Figure 28453 .

    1.Crankshaft Carrier Adaptor No. 1 ‪

    4.Crankshaft Carrier Adaptor No. 4 ‪

    2.Crankshaft Carrier Adaptor No. 2 ‪

    5.Crankshaft Carrier Adaptor No. 5 ‪

    3.Crankshaft Carrier Adaptor No. 3 ‪

    6.Crankshaft Carrier Adaptor No. 6 ‪

    Crankshaft Carrier Adaptor Location

  6. Install connecting rod and piston assembly. Refer to section .
  7. Install the vacuum pump. Refer to section .
  8. Install the oil pump. Refer to section
  9. Install the flywheel housing. Refer to section .
  10. Install the flywheel. Refer to section .
  11. Install oil pickup tube screen. Refer to section .
  12. Install oil pan. Refer to section .
  13. Measure crankshaft end clearance. Refer to section .
  14. Run engine to verify repairs.
Measuring for Crankshaft End Clearance

Measure crankshaft end clearance as follows: ‪

  1. Using a dial gage (see Figure 28459 ), measure crankshaft end clearance.
    1. If crankshaft clearance is not within 0.153-0.304 mm (0.0060-0.0119 in.), install thrust plates of a different thickness (refer to section ); refer to section ; go to step
    2. If crankshaft clearance is within 0.153-0.304 mm (0.0060-0.0119 in.), refer to section ; go to step
    3. 1.Dial Gage ‪

      2.Flywheel ‪

      Measuring Crankshaft End Clearance