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MBE 4000 CRANKSHAFT ASSEMBLY

The crankshaft is precision-forged with seven main bearings and eight custom-forged counter weights, and a vibration damper at the front end. For an exploded view of the crankshaft, main bearings, and main bearing caps, see Figure 41937 . ‪

1. Crankshaft ‪

5. Lower Bearing Shell (center) ‪

2. Upper Bearing Shell(s) ‪

6. Main Bearing Cap(s) ‪

3. Upper Bearing Shell (center) ‪

7. Main Bearing Cap (center) ‪

4. Lower Bearing Shell(s) ‪

8. Main Bearing Cap Bolt ‪

Crankshaft, Main Bearings, and Main Bearing Caps

Crankshaft Removal

Remove the crankshaft as follows: ‪

  1. Remove the engine.

    FALLING ENGINE

    To avoid injury from a falling engine, an adequate lifting device with a spreader bar and sling should be used to lift the engine. The sling and spreader bar should be adjusted so the lifting hooks are vertical to prevent bending the lifter brackets. To ensure proper weight distribution, all provided lifter brackets must be used.

    FALLING ENGINE

    To avoid injury from a falling engine, ensure the engine is securely attached to the engine overhaul stand before releasing the lifting sling.

  2. Mount the engine on an engine stand.
  3. Remove the cylinder heads. Refer to section .
  4. Remove the oil pan and oil pump. Refer to section . Refer to section .
  5. Remove the flywheel and flywheel housing. Refer to section .
  6. Remove the front cover housing. Refer to section .
  7. Remove the pistons. Refer to section .
  8. Turn the crankshaft until the marked gear teeth on the camshaft gear line up with the marked tooth on the crankshaft gear. See Figure 41938 .

    1. Camshaft Gear ‪

    2. Crankshaft Gear ‪

    Aligning the Marked Gear Teeth

  9. Remove the crankshaft gear from the crankshaft. Refer to section .
  10. Mark the order of the main bearing caps, then remove the main bearing-cap bolts. See Figure 41939 .

    Removal Order, Main Bearing Cap Bolts

  11. Loosen the main bearing caps with a plastic hammer, if necessary. Remove the main bearing caps.

    FALLING COMPONENT

    To avoid injury from a falling component, ensure a proper lifting device is used. ‪

  12. Attach a suitable hoist to the crankshaft, using flexible straps to hold the crankshaft without bending or scratching it. Then lift the crankshaft out of the block. See Figure 41940 .

    1. Crankshaft ‪

    3. Hoisting Chain ‪

    2. Flexible Straps ‪

    4. Engine Stand ‪

    Attaching the Hoist

  13. Lift the crankshaft out of the cylinder block. Make sure the crankshaft doesn't twist from side to side. See Figure 41941 .

    1. Crankshaft ‪

    3. Hook of Hoisting Chain ‪

    2. Flexible Straps ‪

    4. Cylinder Block ‪

    Lifting the Crankshaft

    1. Lower the crankshaft gently onto a flat surface covered with clean cardboard.
    2. Remove the hoist.
  14. Mark each upper bearing shell and its corresponding race before removing the bearing shells from the crankcase.
  15. Check all parts for wear or damage. Measure the various crankshaft specifications. Refer to section .

Crankshaft Installation

Install the crankshaft as follows: ‪

  1. Clean the crankshaft oil passages with a wire brush and blow compressed air through the passages. Clean the crankshaft, bearings, and bearing seats with a chamois.
  2. Lubricate the bearing surfaces with a light coating of clean engine oil.
  3. Install the upper bearing shells into the block, in the same order as they were removed. Make sure the locking lugs of the bearing shells fit into the slots of the block bores. Refer to section .

    Note: The center bearing shell halves must be mounted in the center crankcase race and bearing cap (fourth from either end).

  4. Install the lower bearing shells into the main bearing caps, in the same order as they were removed. Make sure the locking lugs are fully seated in the grooves of the bearing caps. Refer to section .
  5. Screw a crankshaft and flywheel guide stud into each end of the crankshaft.

    FALLING COMPONENT

    To avoid injury from a falling component, ensure a proper lifting device is used. ‪

  6. Using a suitable hoist, lower the crankshaft into the block.
  7. As you set the crankshaft into the block, use the guide studs to maneuver the crankshaft into position to align the crankshaft gear with the camshaft gear. Fit the marked gear tooth on the crankshaft gear between the two marked teeth on the camshaft gear. See Figure 41938 .
  8. Install all the main bearing caps (including the center bearing cap), with their bearing shells, on the crankcase journals, as removed. See Figure 41939 .

    Note: Make sure the numbers on the bearing caps are in ascending order, starting from the front of the engine.

  9. Measure the shaft length of the main bearing-cap bolts. Replace any bolts that exceed the maximum shaft length of 156.0 mm (6.14 inches). See Figure 41942 .

    1. Main Bearing-Cap Bolt ‪

    Measuring a Main Bearing-Cap Bolt

  10. Lubricate the main bearing-cap bolts with a light coating of clean engine oil. Install all the M18 x 2 main bearing-cap bolts, in the correct order, as removed. Tighten each one in four stages, listed in Table , stage by stage.

    Max. Shaft Length: mm (in.)

    Tightening Stage

    Torque Value: Nm (lbft)

    156.0 mm (6.14 in.) ‪

    Stage 1 ‪

    100 (74) ‪

    156.0 mm (6.14 in.) ‪

    Stage 2 ‪

    200 (148) ‪

    156.0 mm (6.14 in.) ‪

    Stage 3 ‪

    300-330 (221-243) ‪

    156.0 mm (6.14 in.) ‪

    Stage 4 ‪

    90 degrees ‪

    Tightening Stages, Main Bearing-Cap Bolts
  11. Measure the crankshaft end play (fore-to-aft motion) at the center bearing journal. Refer to section .
  12. Install the pistons. Refer to section .
  13. Install the oil pump and oil pan. Refer to section . Refer to section .
  14. Install the flywheel and flywheel housing. Refer to section .
  15. Install the front cover housing. Refer to section .
  16. Install the cylinder heads. Refer to section .

    FALLING ENGINE

    To avoid injury from a falling engine, an adequate lifting device with a spreader bar and sling should be used to lift the engine. The sling and spreader bar should be adjusted so the lifting hooks are vertical to prevent bending the lifter brackets. To ensure proper weight distribution, all provided lifter brackets must be used.

  17. Remove the engine from the stand.
  18. Install the engine.
Crankshaft Measuring and Inspection

Inspect the crankshaft as follows: ‪

  1. Remove the crankshaft. Refer to section .
  2. Clean the crankshaft with a chamois.
  3. Check the crankshaft for condition. If cracks or fissures are found, replace the crankshaft.
  4. Using the hardness tester (000 589 53 21 00) , test the hardness of the journals. Each journal must pass the hardness test at two thirds of its circumference. If it doesn't, either replace the crankshaft, or have it re-hardened.
    1. Place a hard base underneath the bearing journal to be tested.
    2. Test hardness all the way around the journal circumference. Hardness must be 53 to 59 HRC as listed in Table .

      Description

      Specification in mm (inches)*

      Main Bearing and Connecting Rod Journal Hardness (Rockwell hardness) ‪

      53 to 59 HRC ‪

      Permissible Deviation From True of Crankshaft ‪

      0.09 (0.004) ‪

      Permissible Out-Of-Round for Main and Connecting-Rod Bearing Journals - When New reground ‪

      0.01 (0.0004) ‪

      Permissible Out-Of-Round for Main and Connecting-Rod Bearing Journals - Wear Limit ‪

      0.02 (0.0008) ‪

      Fillet Radii of Main Bearing Journals ‪

      4.2-4.5 (0.165-0.177) ‪

      Fillet Radii of Connecting Rod Bearing Journals ‪

      3.7 - 4.0 (0.146 - 0.157) ‪

      Crown of Main Bearing Journals and Connecting-Rod Journals ‪

      0.000-0.004 (0.0000-0.0002) ‪

      Main Bearing Outside Diameter (diameter of bearing shell housing ‪

      111.000-111.022 (4.3701-4.3709) ‪

      Permissible Imbalance of Crankshaft -at 400 rpm ‪

      0.6 Ncm (0.05 lbin) ‪

      Crankshaft Specifications



  5. Measure the deviation from true of the crankshaft. If the deviation from true is greater than 0.09 mm (0.004 inch), regrind the crankshaft.
    1. Support the crankshaft on a stand, held by the two external journals.
    2. Set up a dial gauge and holder on the center journal, with some preload on the gauge.
    3. Set the dial gauge to "0" (zero).
    4. Turn the crankshaft through one full revolution, and check the dial gauge. If the dial gauge deviates by more than 0.09 mm (0.004 inch), regrind the crankshaft.
  6. Check the crankshaft for dynamic balance. Permissible imbalance is listed in Table .
  7. Using a micrometer, measure the diameters of the main journals and the connecting-rod journals. Measure in both the vertical and horizontal directions on each journal. Refer to section for detailed procedures.
  8. Comparing the two measurements taken above, check each crankshaft main and connecting-rod journal for out-of-round.

    If, for any one journal, the two measurements differ by more than 0.01 mm (0.0004 inch), regrind the crankshaft. ‪

    If, for any one journal, the two measurements differ by more than 0.02 mm (0.0008 inch), replace the crankshaft. Refer to section . ‪

    Listed in Table are the permissible ranges at the various repair stages.

    Size: mm (in.)

    Main Bearing Journal Diameter: mm (in.)

    Connecting-Rod Bearing Journal Diameter: mm (in.)

    Standard ‪

    103.980-104.000 (4.0937-4.0945) ‪

    93.980-94.000 (3.7000-3.7007) ‪

    Undersize - 0.10 (0.004) ‪

    103.880-103.900 (4.0898-4.0905) ‪

    93.880-93.900 (3.6960-3.6968) ‪

    Undersize - 0.25 (0.010) ‪

    103.730-103.750 (4.0839-4.0846) ‪

    93.730-93.750 (3.6901-3.6909) ‪

    Undersize - 0.50 (0.020) ‪

    103.480-103.500 (4.0740-4.0748) ‪

    93.480-93.500 (3.6803-3.6811) ‪

    Undersize - 0.75 (0.030) ‪

    103.230-103.250 (4.0642-4.0650) ‪

    93.230-93.250 (3.6705-3.6712) ‪

    Undersize - 1.00 (0.040) ‪

    102.980-103.000 (4.0543-4.0551) ‪

    92.980-93.000 (3.6606-3.6614) ‪

    Crankshaft Journal Diameters
  9. Measure the width of all the main and connecting-rod journals. See Figure 41944 . Listed in Table are the permissible ranges.

    1. Crankshaft ‪

    2. Hardness Tester ‪

    Journal Measurements

    Type of Journal:

    mm (in.) ‪

    Width in

    mm (in.) ‪

    Main Journal ‪

    46.000-46.250 ‪

    (1.8110-1.8209) ‪

    Connecting-Rod Journal ‪

    44.5-44.6 ‪

    (1.752-1.756) ‪

    Bearing Journal Width
  10. Check the width of the center bearing shell and journal. See Figure 41944 . Listed in Table are the permissible ranges at the various repair stages.

    Size: mm (in.)

    Thrust Bearing Shell Width

    Thrust Bearing Journal Width

    Standard ‪

    45.74-45.81 (1.801-1.804) ‪

    46.000-46.062 (1.8110-1.8135) ‪

    Undersize - 0.50 (0.020) ‪

    46.24-46.31 (1.820-1.823) ‪

    46.500-46.562 (1.8307-1.8331) ‪

    Undersize - 1.00 (0.040) ‪

    46.74-46.81 (1.840-1.843) ‪

    47.000-47.062 (1.8504-1.8528) ‪

    Bearing Shell and Bearing Journal Width
  11. Measure the fillet radius of the main journals and the connecting-rod journals as listed in Table . See Figure 41945 .

    Measuring the Fillet Radius

  12. Measure the crown of the main journals and the connecting-rod journals as listed in Table . See Figure 41946 .

    Measuring the Crown of the Journal

  13. Regrind the main journals. After grinding, see Figure 41944 for dimensions.
    1. Check the outside diameter of each main journal.
    2. Check the width of the center main journal.
    3. Check the width of the remaining main journals.
    4. Check the fillet radius of each main journal.
    5. Check the crown of each main journal.
    6. Check each main journal for out-of-round.
  14. Regrind the connecting-rod journals. After grinding, check the following dimensions.
    1. Check the outside diameter of each connecting-rod journal.
    2. Check the width of the each connecting-rod journal.
    3. Check the fillet radius of each connecting-rod journal.
    4. Check the crown of each connecting-rod journal.
    5. Check each connecting-rod journal for out-of-round.
  15. Install the crankshaft. Refer to section .
    1. When the main bearing caps have been installed, measure the radial play (radial runout) of the crankshaft. Refer to section .
    2. With the crankshaft fully installed, measure the end play (lateral runout) of the crankshaft. Refer to section .
Crankshaft Radial Play Checking

Check the crankshaft radial play as follows: ‪

  1. Clean the bearing races in the crankcase (cylinder block) and the bearing seats in the bearing caps with a chamois.

    Note: The center bearing shell halves must be mounted in the center crankcase race and bearing cap (fourth from either end).

  2. Install the upper bearing shell on the bearing race in the crankcase. The locking lugs of the bearing shells must fit into the slots in the crankcase races. See Figure 41947 .

    1. Crankcase Race ‪

    3. Cylinder Block ‪

    2. Upper Bearing Shell ‪

    4. Bearing Shells Locking Lug ‪

    Installing the Upper Bearing Shell

  3. Install the lower bearing shell on the bearing seat in the bearing cap. The locking lugs in the bearing shells must fit into the grooves in the bearing cap. See Figure 41948 .

    1. Main Bearing Cap ‪

    3. Guide Pin ‪

    2. Lower Bearing Shell ‪

    Installing the Lower Bearing Shell

    Note: The guide pins on the bearing cap ensure correct seating of the cap on the crankcase race.

  4. Install all the main bearing caps (including the center bearing cap) with their bearing shells, on the crankcase journals, pressing them in with the fingers and making sure the guide pins are correctly aligned. See Figure 41949 .

    1. Main Bearing Cap(s) ‪

    3. Bearing Cap Bolts (14 qty.) ‪

    2. Main Bearing Cap (center) ‪

    Installing the Bearing Caps

    Note: Make sure the numbers on the bearing caps are in ascending order, starting from the front of the engine.

  5. Lubricate the main bearing cap bolts with a light coating of clean engine oil. Install them on the main bearing caps. See Figure 41950 . Refer to section for instructions and tightening torques.

    1. Cylinder Block ‪

    3. Bearing-Cap Bolt ‪

    2. Main Bearing Cap ‪

    4. Crankshaft Gear ‪

    Installing the Main Bearing Caps

  6. Using a dial gauge and quick-release calipers, measure the inside diameter of each of the main bearings. See Figure 41951 .
    1. Measure vertically from the top to the bottom of the bore. (see Figure 41951 , A.)
    2. Measure 30 degrees counterclockwise from the separation point of the bearing shells. (see Figure 41951 , B.)
    3. Measure 30 degrees clockwise from the separation point of the bearing shells. (see Figure 41951 , C.)
    4. 1. Bearing Cap Bolts ‪

      3. Main Bearing Shell ‪

      2. Main Bearing Cap ‪

      4. Crankcase Race ‪

      Measuring the Inside Diameter of the Main Bearing Shells

  7. If any one of the readings is not within tolerances listed in Table , then replace the main bearing shells as applicable.

    Size: mm (in.)

    Main Bearing Inside Diameter

    Main Journal Outside Diameter

    Standard ‪

    104.060-104.106 (4.0968-4.0987) ‪

    103.980-104.000 (4.0937-4.0945) ‪

    Undersize - 0.10 (0.004) ‪

    103.960-104.006 (4.0929-4.0947) ‪

    103.880-103.900 (4.0898-4.0905) ‪

    Undersize - 0.25 (0.010) ‪

    103.810-103.856 (4.0870-4.0888) ‪

    103.730-103.750 (4.0839-4.0846) ‪

    Undersize - 0.50 (0.020) ‪

    103.560-103.606 (4.0772-4.0790) ‪

    103.480-103.500 (4.0740-4.0748) ‪

    Undersize - 0.75 (0.030) ‪

    103.310-103.356 (4.0673-4.0691) ‪

    103.230-103.250 (4.0642-4.0650) ‪

    Undersize - 1.00 (0.040) ‪

    103.060-103.106 (4.0575-4.0593) ‪

    102.980-103.000 (4.0543-4.0551) ‪

    Bearing Shell and Bearing Journal Diameter

    Note: New bearing shells are supplied ready for installation. Do not machine them or remove any material from them. Refer to section .

  8. Remove the bearing caps.

    Note: If the bolts are going to be used again, check their length.

  9. Using a micrometer, measure the outside diameter of the main journals. See Figure 41952 .

    1. Micrometer ‪

    2. Main Journal ‪

    Measuring the Outside Diameter of the Main Journals

    Note: To obtain a correct value for crankshaft radial play, the diameters of each bearing bore and its corresponding journal must belong to the same repair stage (both must be "Standard," "Undersize - 0.004 inch," etc.).

  10. Calculate the radial play (up-and-down movement) of the main bearings on the crankshaft journals.

    If the radial play is less than 0.060 mm (0.0024 inch), or more than 0.126 mm (0.0050 inch) as listed in Table , then replace the crankshaft. ‪

    Description

    mm (inch)

    Main Journal Radial Play ‪

    0.060-0.126 (0.0024-0.0050) ‪

    Crankshaft Radial Play
    1. For the main bearing shell, note the inside diameter of the bearing shell. Example: Ds = 4.0875 inches.
    2. For the main bearing journal, note the outside diameter of the journal. Example: Dj = 4.0850 inches.
    3. From the value for the bearing shell diameter, subtract the value for the journal diameter. This result is the radial play. Example: Ds Dj = 0.0025 inch.

      Note: In the above example, both measurements belonged to repair stage "Undersize - 0.010 inch." Listed in Table is the correct repair stage for each measurement.

  11. Install the crankshaft into the crankcase. Refer to section .
  12. Install the engine.
Crankshaft End Play Checking

Check the crankshaft end play as follows: ‪

  1. Remove the crankshaft. Refer to section .
  2. Check the width of the center main bearing journal. If damage or cracks are present, replace the crankshaft. See Figure 41953 .

    Measuring the Width of the Center Journal

  3. Check the width of the center main bearing shell. If damage or cracks are present, replace the crankshaft. See Figure 41954 .

    Measuring the Width of the Center Main Bearing Shell

    Note: To obtain a correct value for crankshaft end play, the width of each bearing shell and its corresponding journal must belong to the same repair stage (both must be "Standard," "Undersize - 0.020 inch," etc.).

  4. Calculate the end play, or axial play, (fore-to-aft movement) of the crankshaft.

    If the end play is less than 0.190 mm (0.0074 inch), or more than 0.322 mm (0.0127 inch) as listed in Table , then replace the crankshaft. ‪

    Description

    mm (inch)

    End Play (Axial Play) Measured at Center Bearing Journal ‪

    0.190-0.322 (0.0074-0.0127) ‪

    Crankshaft End Play
    1. For the center main bearing journal, note the width (thickness) of the bearing journal. Example: Wm = 1.8120 inches.
    2. For the center main bearing shell, note the width (thickness) of the bearing shell. Example: Ws =1.8030 inches.
    3. From the value for the journal width, subtract the value for the bearing shell width. This result is the end play. Example: Wm Ws = 0.0090 inch.

      Note: In the above example, both measurements belonged to repair stage "Standard." If necessary, listed in Table are the correct repair stages for each measurement.

      Size: mm (in.)

      Center Bearing Shell Width

      Center Bearing Journal Width

      Standard ‪

      45.74-45.81 (1.801-1.804) ‪

      46.000-46.062 (1.8110-1.8135) ‪

      Undersize - 0.020 (0.50) ‪

      46.24-46.31 (1.820-1.823) ‪

      46.500-46.562 (1.8307-1.8331) ‪

      Undersize - 1.00 (0.040) ‪

      46.74-46.81 (1.840-1.843) ‪

      47.000-47.062 (1.8504-1.8528) ‪

      Bearing Shell and Bearing Journal Width
  5. Install the crankshaft. Refer to section .
  6. Using a dial gauge and holder, measure the end play of the crankshaft. Measure at the front end of the crankshaft, with the crankshaft fully installed and all the bearing caps tightened to the correct torque. See Figure 41955 .

    1. Dial Gauge ‪

    3. Crankshaft ‪

    2. Dial Gauge Holder ‪

    4. Screwdriver ‪

    Measuring the End Play of the Crankshaft

    1. Set up a dial gauge and a dial gauge holder on the front end of the crankshaft. Set the dial gauge to 5 mm (0.2 inch) preload.
    2. Move the crankshaft all the way forward by prying on one of the bearing caps, then reset the dial gauge to "0" (zero).
    3. Move the crankshaft all the way aft. Note the end play on the dial gauge.
    4. If the end play does not correspond to the calculated amount (in the example above: 0.0090 inch), replace the crankshaft.
  7. Install the engine.

Crankshaft Gear Replacement

Replace the crankshaft gear as follows: ‪

  1. Remove the engine from the vehicle.
  2. Remove the flywheel housing. Refer to section .
  3. Rotate the crankshaft until the marked gear tooth on the crankshaft gear is aligned between the two similarly marked teeth on the camshaft gear.
  4. Pull the crankshaft gear off the end of the crankshaft. If necessary, use a plastic hammer to loosen the gear. See Figure 41956 .

    1. Crankshaft ‪

    3. Crankshaft Gear ‪

    2. Guide Pin ‪

    Removing the Crankshaft Gear

  5. Remove the crankshaft from the engine. Refer to section .
  6. Clean the crankcase (cylinder block and oil pan). Remove all burrs and sharp edges from the oil passage holes.
  7. Press the gear onto the end of the crankshaft. Make sure the chamfer on the gear is facing outward. See Figure 41956 .
  8. Install the crankshaft. Refer to section .
  9. Install the engine.