Isuzu Ascender 2003-05

Camshaft, Bearings & Lifters

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Bearing Replacement



5.3L Engine


Click image to see an enlarged view

Fig. Engine and bearings

Prior to bearing removal, inspect the camshaft bearings for loose fit in the engine block bearing bores. Repair or replace the components, as required.

Click image to see an enlarged view

Fig. Bearing expander and driver

  1. Select the expanding driver 4-8 and washer 2 or 3.
  2.  
  3. Assemble the tool.
  4.  
  5. Insert the tool through the front of the engine block and into the bearing.
  6.  
  7. Tighten the expander assembly 15 nut until snug.
  8.  
  9. Push the guide cone 1 into the front camshaft bearing location in order to align the tool.
  10.  
  11. Drive the bearing from the block bore.
  12.  
  13. Repeat the above procedures in order to remove the remaining bearings.
    NOTE
    Important: In order to remove the front camshaft bearing, operate the tool from the rear of the block, using the guide cone in the rear camshaft bearing bore location.


    NOTE
    To install or remove the expanding driver, always push on or pull from the ends. Pressure on the outside diameter may cause a bind against the rubber expanding sleeve.


    NOTE
    The engine block camshaft bearing bores are machined for 3 different Outside Diameter size bearings. Position 1 and 5 are the largest diameter bores. Position 3 is the smallest diameter bore. Position 2 and 4 are the intermediate size bores. The Inside Diameter for all camshaft bearings is the same size.



    Click image to see an enlarged view

    Fig. Bearing removal



    Click image to see an enlarged view

    Fig. Engine block

  14.  
  15. Measure the engine block camshaft bearing bores (1-5) in order to identify the correct OD size bearing for each position.

    Click image to see an enlarged view

    Fig. Bearing expander and driver

  16.  
  17. Select the expanding driver 4-8 and washer 2 or 3.
  18.  
  19. Assemble the tool.
  20.  
  21. Insert the tool through the front of the engine block and into the bearing.

    Click image to see an enlarged view

    Fig. Engine block and tool

  22.  
  23. Tighten the expander assembly nut until snug.
  24.  
  25. Push the cone 2 into the front camshaft bearing location in order to align the tool.
  26.  
  27. Drive the bearing into the block bore.
  28.  
  29. Install the front and rear bearings to the block.

    Click image to see an enlarged view

    Fig. Bearing Installation

  30.  

Inspection



  1. Clean the camshafts with cleaning solvent.
  2.  
  3. Inspect the camshafts for the following conditions.
    1. Scored camshaft journals.
    2.  
    3. Damaged camshaft lobes.
    4.  
    5. Damaged camshaft sprocket locator pin slots.
    6.  
    7. Damaged threads.
    8.  

  4.  

Measure the camshaft lobes using a micrometer. The intake camshaft lobes should be a minimum of 41.5 mm 1.635 in. The exhaust camshaft lobes should be a minimum of 41 mm 1.615 in.

Click image to see an enlarged view

Fig. Camshaft and micrometer

  1. Measure the camshaft runout.
  2.  
  3. Set the camshaft in V-blocks between the centers.
  4.  
  5. Measure the intermediate camshaft journal.
  6.  
  7. Measure the camshaft lobe lift.
  8.  
  9. Lubricate the camshaft to V-block contact areas with engine oil.
  10.  
  11. Set the camshaft on V-blocks.
  12.  
  13. Measure the camshaft lobe lift.
    NOTE
    If the runout or camshaft lobe lift is not within specifications, replace the camshaft.



    Click image to see an enlarged view

    Fig. Camshaft inspection

  14.  

Removal & Installation



4.2L Engine
  1. Before servicing the vehicle, refer to the Precautions section.
  2.  
  3. Disconnect the negative battery cable.
  4.  
  5. Discharge and recover the refrigerant from the air conditioning system, using the proper equipment.
  6.  
  7. Remove or disconnect the following:

    Intake manifold
     
    A/C line from the oil level indicator tube
     
    A/C line from the accumulator
     
    A/C bracket bolt from the engine lift hook
     
    Engine lift bracket
     
    Ignition control module electrical connectors
     
    Ignition control module bolts and module
     

  8.  


WARNING
Be careful not to damage the clips that hold the harness housing in place.



Engine electrical harness housing from the camshaft cover
 
Fuel injection harness electrical connector
 
Camshaft cover bolts and cover
 
Exhaust and intake sprocket bolts
 

  1. Install a suitable sprocket holding tool onto the cylinder head and adjust the horizontal bolts into the camshaft sprockets to maintain timing chain tension and avoid disturbing the timing chain components.
  2.  
  3. Carefully move the sprockets with the timing chain off of the camshafts.
  4.  


NOTE
Make sure to place the camshaft caps in a rack to keep them in order, so they may be installed in their original locations.

  1. Remove or disconnect the following:

    Camshaft cap bolts and caps
     
    Camshafts
     

  2.  

To install:

  1. Coat the camshaft journals with engine oil.

    Camshafts, in their original position
     
    Camshaft caps, in their original locations. Tighten the bolts to 106 inch lbs. (12 Nm).
     

  2.  
  3. Carefully place the camshaft sprockets back onto the camshafts and remove the holding tool.
  4.  
  5. Install or connect the following:

    Intake camshaft sprocket washer and bolt and the exhaust camshaft actuator bolt. Tighten the intake camshaft sprocket bolt to 22 ft. lbs. (30 Nm), plus an additional 135 degrees and the exhaust camshaft actuator bolt to 18 ft. lbs. (25 Nm), plus an additional 135 degrees.
     
    New camshaft cover seal
     
    New rubber ignition control module seals
     
    Camshaft cover and bolts. Tighten the bolts to 89 inch lbs. (10 Nm).
     
    Ignition control module. Tighten the bolts to 89 inch lbs. (10 Nm).
     
    Ignition control module electrical connectors
     
    Fuel injector electrical connectors
     
    Engine electrical harness housing
     
    A/C line bracket to the oil level indicator tube stud and secure with the nut. Tighten the nut to 62 inch lbs. (7 Nm).
     
    Engine lift bracket and secure the lift hook with the bolts. Tighten the bolts to 37 ft. lbs. (50 Nm).
     
    A/C line bracket to the engine lift bracket. Tighten the bolt to 89 inch lbs. (10 Nm).
     
    Intake manifold
     

  6.  
  7. Using the proper equipment, recharge the A/C system.
  8.  

  1. Before servicing the vehicle, refer to the precautions section.
  2.  
  3. Disconnect the negative battery cable.
  4.  
  5. Discharge and recover the refrigerant from the air conditioning system, using the proper equipment.
  6.  
  7. Remove or disconnect the following:
    WARNING
    Be careful not to damage the clips that hold the harness housing in place.



    Intake manifold
     
    A/C line from the oil level indicator tube
     
    A/C line from the accumulator
     
    A/C bracket bolt from the engine lift hook
     
    Engine lift bracket
     
    Ignition control module electrical connectors
     
    Ignition control module bolts and module
     



    Engine electrical harness housing from the camshaft cover
     
    Fuel injection harness electrical connector
     
    Camshaft cover bolts and cover
     
    Exhaust and intake sprocket bolts
     

  8.  
  9. Install a suitable sprocket holding tool onto the cylinder head and adjust the horizontal bolts into the camshaft sprockets to maintain timing chain tension and avoid disturbing the timing chain components.
  10.  
  11. Carefully move the sprockets with the timing chain off of the camshafts.
    NOTE
    Make sure to place the camshaft caps in a rack to keep them in order, so they may be installed in their original locations.

  12.  
  13. Remove or disconnect the following:

    Camshaft cap bolts and caps
     
    Camshafts
     

  14.  

To install:

  1. Coat the camshaft journals with engine oil.

    Camshafts, in their original position
     
    Camshaft caps, in their original locations. Tighten the bolts to 106 inch lbs. (12 Nm).
     

  2.  
  3. Carefully place the camshaft sprockets back onto the camshafts and remove the holding tool.
  4.  
  5. Install or connect the following:

    Intake camshaft sprocket washer and bolt and the exhaust camshaft actuator bolt. Tighten the intake camshaft sprocket bolt to 22 ft. lbs. (30 Nm), plus an additional 135 degrees and the exhaust camshaft actuator bolt to 18 ft. lbs. (25 Nm), plus an additional 135 degrees.
     
    New camshaft cover seal
     
    New rubber ignition control module seals
     
    Camshaft cover and bolts. Tighten the bolts to 89 inch lbs. (10 Nm).
     
    Ignition control module. Tighten the bolts to 89 inch lbs. (10 Nm).
     
    Ignition control module electrical connectors
     
    Fuel injector electrical connectors
     
    Engine electrical harness housing
     
    A/C line bracket to the oil level indicator tube stud and secure with the nut. Tighten the nut to 62 inch lbs. (7 Nm).
     
    Engine lift bracket and secure the lift hook with the bolts. Tighten the bolts to 37 ft. lbs. (50 Nm).
     
    A/C line bracket to the engine lift bracket. Tighten the bolt to 89 inch lbs. (10 Nm).
     
    Intake manifold
     

  6.  
  7. Using the proper equipment, recharge the A/C system.
  8.  

5.3L Engine
  1. Before servicing the vehicle, refer to the Precautions section.
  2.  
  3. Disconnect the negative battery cable.
  4.  
  5. Discharge and recover the refrigerant from the air conditioning system, using the proper equipment.
  6.  
  7. Remove or disconnect the following:

    Condenser
     
    Cylinder head and gasket
     
    Valve lifter guide bolts
     
    Valve lifters and guide
     

  8.  


NOTE
If the lifters are stuck in the bores due to built up deposits, use Valve Lifter Remover tool No. J 3049-A or equivalent to remove the lifters



Valve lifters from the guide
 


NOTE
Make sure to keep the lifters in order as you are removing them. They must be installed in their original locations.



Click image to see an enlarged view

Fig. Valve lifters and guides-5.3L engine

Remove the lifters from the guides, making sure to keep them in order-5.3L engine

  1. Clean and inspect the lifters for damage.

    Camshaft sensor bolt and sensor
     

  2.  
  3. Rotate the crankshaft until the timing marks on the crankshaft and camshaft sprockets are aligned.

    Camshaft sprocket bolts
     

  4.  


    Click image to see an enlarged view

    Fig. Make sure the crankshaft and camshaft timing marks are aligned



WARNING
Do NOT turn the crankshaft after the timing chain has been removed to avoid damaging the pistons or valves!



Camshaft sprocket and reposition the timing chain
 
Camshaft retaining bolts and retainer
 
Camshaft by installing three M8-1.25 x 4.0 in. (M8-1.25 x 1.00mm) bolts in the front of the camshaft to act as a handle; then, remove the camshaft while turning slightly from side to side, as necessary. Remove the bolts from the camshaft.
 


NOTE
Take care not to damage the camshaft bearings when removing the camshaft.

  1. Clean and inspect the camshaft and bearings.
  2.  

To install:


NOTE
If the camshaft must be replaced, you must also replace the lifters.

  1. Lubricate the camshaft journals with clean engine oil.
  2.  
  3. Install or connect the following:

    Three bolts used during removal into the bolt hold in the front of the camshaft
     
    Camshaft carefully into the engine block, using the bolts as a handle. Remove the bolts.
     
    Camshaft retainer and bolts. Make sure the retaining plate is installed with the sealing gasket facing the engine block. Tighten the bolts to 18 ft. lbs. (25 Nm).
     

  4.  
  5. Properly locate the camshaft sprocket locating pin with the cam sprocket alignment hole. The sprocket teeth and timing chain must mesh. The camshaft and crankshaft sprocket alignment marks MUST be aligned properly. Locate the camshaft sprocket alignment mark in the 6 o-clock position. It may be necessary to rotate the camshaft or crankshaft to align the marks.

    Camshaft sprocket and timing chain
     
    Camshaft sprocket bolts and tighten to 26 ft. lbs. (35 Nm)
     
    Camshaft sensor O-ring, after making sure it is not damaged and lubricating it with clean engine oil
     
    Camshaft sensor and bolt. Torque the bolt to 18 ft. lbs. (25 Nm).
     

  6.  
  7. Lubricate the valve lifters and engine block lifter bores with clean engine oil.
  8.  
  9. Install or connect the following:

    Lifters into the lifter guides. Align the area on top of the lifter with the flat area in the lifter guide bore. Push the lifter completely into the guide bore.
     
    Valve lifters and guide to the engine block
     
    Valve lifter guide bolt and tighten to 106 inch lbs. (12 Nm)
     
    Cylinder head and gasket
     
    Condenser
     

  10.  
  11. Using the proper equipment, recharge the A/C system.
  12.  

  1. Before servicing the vehicle, refer to the precautions section.
  2.  
  3. Disconnect the negative battery cable.
  4.  
  5. Discharge and recover the refrigerant from the air conditioning system, using the proper equipment.
  6.  
  7. Remove or disconnect the following:
    NOTE
    If the lifters are stuck in the bores due to built up deposits, use Valve Lifter Remover tool No. J 3049-A or equivalent to remove the lifters


    NOTE
    Make sure to keep the lifters in order as you are removing them. They must be installed in their original locations.



    Condenser
     
    Cylinder head and gasket
     
    Valve lifter guide bolts
     
    Valve lifters and guide
     



    Valve lifters from the guide
     



    Click image to see an enlarged view

    Fig. Valve lifters and guides-5.3L engine

  8.  
  9. Clean and inspect the lifters for damage.

    Camshaft sensor bolt and sensor
     

  10.  
  11. Rotate the crankshaft until the timing marks on the crankshaft and camshaft sprockets are aligned.
    WARNING
    Do NOT turn the crankshaft after the timing chain has been removed to avoid damaging the pistons or valves!


    NOTE
    Take care not to damage the camshaft bearings when removing the camshaft.



    Camshaft sprocket bolts

    Click image to see an enlarged view

    Fig. Make sure the crankshaft and camshaft timing marks are aligned

     



    Camshaft sprocket and reposition the timing chain
     
    Camshaft retaining bolts and retainer
     
    Camshaft by installing three M8-1.25 x 4.0 in. (M8-1.25 x 1.00mm) bolts in the front of the camshaft to act as a handle; then, remove the camshaft while turning slightly from side to side, as necessary. Remove the bolts from the camshaft.
     

  12.  
  13. Clean and inspect the camshaft and bearings.
  14.  

To install:


NOTE
If the camshaft must be replaced, you must also replace the lifters.

  1. Lubricate the camshaft journals with clean engine oil.
  2.  
  3. Install or connect the following:

    Three bolts used during removal into the bolt hold in the front of the camshaft
     
    Camshaft carefully into the engine block, using the bolts as a handle. Remove the bolts.
     
    Camshaft retainer and bolts. Make sure the retaining plate is installed with the sealing gasket facing the engine block. Tighten the bolts to 18 ft. lbs. (25 Nm).
     

  4.  
  5. Properly locate the camshaft sprocket locating pin with the cam sprocket alignment hole. The sprocket teeth and timing chain must mesh. The camshaft and crankshaft sprocket alignment marks MUST be aligned properly. Locate the camshaft sprocket alignment mark in the 6 o-clock position. It may be necessary to rotate the camshaft or crankshaft to align the marks.

    Camshaft sprocket and timing chain
     
    Camshaft sprocket bolts and tighten to 26 ft. lbs. (35 Nm)
     
    Camshaft sensor O-ring, after making sure it is not damaged and lubricating it with clean engine oil
     
    Camshaft sensor and bolt. Torque the bolt to 18 ft. lbs. (25 Nm).
     

  6.  
  7. Lubricate the valve lifters and engine block lifter bores with clean engine oil.
  8.  
  9. Install or connect the following:

    Lifters into the lifter guides. Align the area on top of the lifter with the flat area in the lifter guide bore. Push the lifter completely into the guide bore.
     
    Valve lifters and guide to the engine block
     
    Valve lifter guide bolt and tighten to 106 inch lbs. (12 Nm).
     
    Cylinder head and gasket
     
    Condenser
     

  10.  
  11. Using the proper equipment, recharge the A/C system.
  12.  

 
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