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MBE 4000 CAMSHAFT AND CAMSHAFT SENSOR

The camshaft is made of induction-hardened steel and has seven main bearings. Each cylinder has cams for intake and exhaust valves and a unit pump. ‪

Camshaft Removal

Remove the camshaft as follows: ‪

Note: Before removing the camshaft, clean the engine to prevent road dirt, grease, or other foreign matter from contaminating the exposed gears and other engine parts.

  1. Drain the engine oil.

    PERSONAL INJURY

    To avoid injury when removing or installing a heavy engine component, ensure the component is properly supported and securely attached to an adequate lifting device to prevent the component from falling.

    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. Remove the engine from the vehicle and support it on a stand.
  3. Remove the unit pumps. Refer to section .
  4. Remove the vibration damper. Refer to section .
  5. Remove the fan support.
  6. Remove the eight mounting bolts attaching the camshaft front cover to the cylinder block. See Figure 42079 .

    Removing the Camshaft Front Cover

  7. Remove the fuel pump drive gear from the front of the camshaft. See Figure 42080 .

    1. Drive Gear Mounting Bolt ‪

    4. Fuel Pump Drive Gear ‪

    2. Front Camshaft Cover ‪

    5. Front of Camshaft ‪

    3. Cover Mounting Bolt ‪

    6. Fuel Pump Driven Gear ‪

    Camshaft Assembly

  8. Remove the rocker arm assembly and pushrods. Refer to section .
  9. Turn the engine on the stand until it is upside down.
  10. Remove the oil pan. Refer to section .
  11. Remove the flywheel housing. Refer to section .

    NOTICE:

    Do not damage the camshaft bearings in the crankcase. If the camshaft bearings are damaged, the crankcase will have to be replaced.

  12. Attach the camshaft guide tool (J 46183 or 457 589 00 14 00) to the front of the camshaft. See Figure 42081 .

    1. Front of Camshaft ‪

    Attaching the Camshaft Guide Tool

  13. From the gear end (rear of the engine), carefully remove the camshaft from the block. See Figure 42081 .
  14. Pull the tappets (valve lifters) out of the block. Mark the tappets, in order, as removed. See Figure 42082 .

    1. Cylinder Block ‪

    3. Tappet (valve lifter) ‪

    2. Camshaft Entry Hole ‪

    4. Fuel Pump Driven Gear ‪

    Removing the Tappets

  15. Clean and inspect the tappets. Replace the tappets if there are signs of damage or wear, or if any of the measurements do not meet the specifications listed in Table .

    Description

    Repair Stage

    Specifications, mm (inch)

    Tappet Outside Diameter ‪

    Standard ‪

    29.931-29.952 (1.1784-1.1792) ‪

    Tappet Outside Diameter ‪

    Repair Stage I ‪

    30.444-30.465 (1.1986-1.1994) ‪

    Tappet Housing Diameter (in cylinder block) ‪

    Standard ‪

    30.000-30.021 (1.1811-1.1819) ‪

    Tappet Housing Diameter (in cylinder block) ‪

    Repair Stage I ‪

    30.500-30.525 (1.2008-1.2018) ‪

    Valve Tappet Specifications
    1. Measure the outside diameter of each tappet.
    2. Measure the diameter of the tappet housing in the cylinder block.
  16. Inspect the camshaft. Refer to section .

Camshaft Installation

Install the camshaft as follows: ‪

  1. Lubricate the tappets with a light coating of clean engine oil.
  2. Install the tappets in the block, in order, as removed.

    NOTICE:

    Do not damage the camshaft bearings in the crankcase. If the camshaft bearings are damaged, the crankcase will have to be replaced.

  3. Install the camshaft.
    1. Lubricate the cams and camshaft journals with a light coating of clean engine oil.
    2. Attach the camshaft guide tool (J 46183 or 457 589 00 14 00) to the camshaft.
    3. Rotate the camshaft until the marked gear teeth on the camshaft gear are aligned with the marked tooth on the crankshaft gear. See Figure 42083 .
    4. 1. Camshaft Gear ‪

      2. Crankshaft Gear ‪

      Aligning the Marked Gear Teeth

    5. Carefully insert the camshaft into the block.
  4. Install the flywheel housing. Refer to section .
  5. Install the oil pan. Refer to section .
  6. Install the fuel pump drive gear on the front of the camshaft, as removed. Torque the bolts to 60 Nm (44 lbft.)
  7. Turn the engine on the stand until it is right side up.
  8. Install the unit pumps. Refer to section .
  9. Install the camshaft front cover on the cylinder block, as removed. Torque the mounting bolts to 50 Nm (37 lbft.)
  10. Install the fan support.
  11. Install the vibration damper. Refer to section .
  12. Lubricate the pushrods with a light coating of clean engine oil. Install the pushrods and the rocker arm assembly. Refer to section .

    FALLING COMPONENT

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

  13. Remove the engine from the stand and install it on the vehicle.
  14. Fill the engine with oil.
Camshaft Inspection

Inspect the camshaft as follows: ‪

Note: To get a correct hardness reading, it is critical to place a hard base below the cam or bearing journal.

  1. Using the hardness tester (000 589 20 21 00) , inspect the hardness of the cams and bearing journals at the camshaft. A hard base should be placed below the cam or bearing journal to be inspected. See Figure 42084 .

    1. Camshaft ‪

    Inspecting Cam Hardness

  2. Measure the diameter of each bearing journal. Measure the diameter of the bushing at each journal. See Figure 42085 .

    1. Camshaft Gear ‪

    2. Dial Gauge ‪

    Measuring the Cam Rise

  3. Mount the camshaft at the outer journals.

    Note: For all of the following steps, use a dial gauge.

  4. Measure the radial runout of the cam basic circle.
  5. Measure the cam rise of the intake valve cams. See Figure 42085 , Ref. I.
  6. Measure the cam rise of the exhaust valve cams. See Figure 42085 , Ref. E.
  7. Measure the cam rise of the unit pump valve cams. See Figure 42085 , Ref. U.
  8. Replace the camshaft if any of the measurements do not meet the specifications listed in Table .

    What To Measure

    Where To Measure

    Value: mm (inch) Unless otherwise noted

    Hardness of Surface ‪

    At Cams and Journals ‪

    5763 HRC ‪

    Camshaft Radial Runout When Mounted on Outer Bearing Journals ‪

    At Gear Seat ‪

    0.020 (0.0008) ‪

    Camshaft Radial Runout When Mounted on Outer Bearing Journals ‪

    At Cam Circle ‪

    0.025 (0.0010) ‪

    Camshaft Radial Runout When Mounted on Outer Bearing Journals ‪

    At Camshaft Journals ‪

    0.030 (0.0012) ‪

    Minimum Valve Cam RiseAbove Basic Circle ‪

    Intake Valve ‪

    7.3 (0.29) ‪

    Minimum Valve Cam RiseAbove Basic Circle ‪

    Exhaust Valve ‪

    8.2 (0.32) ‪

    Camshaft Journal Diameter ‪

    For New Camshaft ‪

    81.89381.928 (3.22413.2255) ‪

    Bushing Diameter ‪

    At Camshaft Journals ‪

    82.00082.035 (3.22833.2297) ‪

    Gear Back Lash ‪

    Cam Gear to Crank Gear ‪

    0.0740.176 (0.00290.0069) ‪

    Gear Back Lash ‪

    Cam Gear to Air Compressor Gear ‪

    0.0820.168 (0.00320.0066) ‪

    Camshaft Specifications

Camshaft Sensor Replacement

Replace the camshaft sensor as follows: ‪

  1. Disconnect the electrical connector. See Figure 42086 .

    1. Camshaft Sensor ‪

    2. Crank Angle Position Sensor ‪

    Camshaft Sensor Installation

  2. Remove the sensor from the access hole in the flywheel housing.
  3. Install a new sensor in the flywheel housing.
  4. Connect the electrical connector.

Note: Be sure that the correct electrical connector is connected to the sensor.