Astro, Safari 1997-2005

Camshaft, Bearings & Lifters

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Bearing Replacement




NOTE
Camshaft Bearing Service Kit J 33049 or equivalent will be needed to replace the camshaft bearings.



Click image to see an enlarged view

Fig. Select the cone (1), the handle (10), the expanding driver (4-8), the washer (2 or 3) and the expander assembly (15)

  1. Select the cone (1), the handle (10), the expanding driver (4-8), the washer (2 or 3) and the expander assembly (15) from the J 33049.
  2.  
  3. Assemble the J-33049 .
    CAUTION
    Wear safety glasses in order to avoid eye damage.


    NOTE
    A loose camshaft bearing may be caused by an enlarged, out-of-round, or damaged engine block camshaft bearing bore. Always remove the camshaft inner bearings #2 and #3 first. The camshaft outer bearings #1 and #4 serve as a guide for the J 33049.



    Click image to see an enlarged view

    Fig. Assemble the J 33049 as shown

  4.  
  5. Remove the camshaft inner bearings #2 and #3.
    1. Insert the J 33049 through the front of the engine block and into the camshaft inner bearing #2.
    2.  
    3. Tighten the J 33049 expander assembly nut until snug.
    4.  
    5. Push the J 33049 guide cone into the camshaft front bearing in order to align the J 33049 .
    6.  
    7. Drive the camshaft inner bearing #2 from the camshaft inner bearing bore #2.
    8.  
    9. Loosen the J 33049 expander assembly nut.
    10.  
    11. Remove the camshaft inner bearing #2 from the J 33049 expander assembly.
    12.  
    13. Insert the J 33049 expander assembly into the camshaft inner bearing #3.
    14.  
    15. Tighten the J 33049 expander assembly nut until snug.
    16.  
    17. Push the J 33049 guide cone into the camshaft front bearing in order to align the J 33049 .
    18.  
    19. Drive the camshaft inner bearing #3 from the camshaft inner bearing bore #3.
    20.  
    21. Loosen the J 33049 expander assembly nut.
    22.  
    23. Remove the camshaft inner bearing #3 from the J 33049 expander assembly.
    24.  

  6.  
  7. Remove the J 33049 from the engine block.
  8.  
  9. Remove the camshaft outer bearings #1 and #4.
    1. Insert the J 33049 into the camshaft outer bearing #1.
    2.  
    3. Tighten the J 33049 expander assembly nut until snug.
    4.  
    5. Drive the camshaft outer bearing #1 from the camshaft outer bearing bore #1.
    6.  
    7. Loosen the J 33049 expander assembly nut.
    8.  
    9. Remove the camshaft outer bearing #1 from the J 33049 expander assembly.
    10.  
    11. Remove the J 33049 from the engine block.
    12.  
    13. Insert the J 33049 into the camshaft outer bearing #4.
    14.  
    15. Tighten the J 33049 expander assembly nut until snug.
    16.  
    17. Drive the camshaft outer bearing #4 from the camshaft outer bearing bore #4.
    18.  
    19. Loosen the J 33049 expander assembly nut.
    20.  
    21. Remove the camshaft outer bearing #4 from the J 33049 expander assembly.
    22.  

  10.  
  11. Remove the J 33049 from the engine block.
  12.  
  13. Discard the camshaft bearings.
  14.  

To install:


NOTE
Camshaft Bearing Service Kit J-33049 or equivalent will be needed to replace the camshaft bearings.



Click image to see an enlarged view

Fig. When installing the camshaft bearings make sure that the camshaft bearing lubrication hole is located above the 3 o'clock position (1) or the 9 o'clock position (2)


NOTE
When installing the camshaft bearings make sure that the camshaft bearing lubrication hole is located above the 3 o'clock position (1) or the 9 o'clock position (2). The proper positioning of the camshaft bearing lubrication hole is in order to ensure the best lubrication of the engine camshaft journals.



Click image to see an enlarged view

Fig. Assemble the J 33049 handle (10), the expanding driver (4-8), the washer (2 or 3) and the expander assembly (15)

  1. Assemble the J 33049 handle (10), the expanding driver (4-8), the washer (2 or 3) and the expander assembly (15).
    CAUTION
    Wear safety glasses in order to avoid eye damage.


    NOTE
    The camshaft bearings vary in size. When ordering the new camshaft bearings, be sure to order the correct camshaft bearings for the application to be serviced. Always install the camshaft outer bearings #1 and #4 first. The camshaft outer bearings serve as a guide for the J 33049 and help center the camshaft inner bearings during the installation process.



    Click image to see an enlarged view

    Fig. Assemble the J 33049 as shown

  2.  
  3. Install the NEW camshaft outer bearings #4 and #1.
    1. Install the NEW camshaft outer bearing #4 onto the J 33049 expander assembly.
    2.  
    3. Tighten the J 33049 expander assembly nut until snug.
    4.  
    5. Align the lubrication hole of the camshaft outer bearing #4 above the 3 o'clock position or the 9 o'clock position of the camshaft outer bearing bore #4 at the rear of the engine block.
    6.  
    7. Drive the camshaft outer bearing #4 into the camshaft outer bearing bore #4 at the rear of the engine block.
    8.  
    9. Loosen the J 33049 expander assembly nut.
    10.  
    11. Remove the camshaft outer bearing #4 from the J 33049 expander assembly.
    12.  
    13. Install the NEW camshaft outer bearing #1 onto the J 33049 expander assembly.
    14.  
    15. Tighten the J 33049 expander assembly nut until snug.
    16.  
    17. Align the lubrication hole of the camshaft outer bearing #1 above the 3 o'clock position or the 9 o'clock position of the camshaft outer bearing bore #1 at the front of the engine block.
    18.  
    19. Drive the camshaft outer bearing #1 into the camshaft outer bearing bore #1 at the front of the engine block.
    20.  
    21. Loosen the J 33049 expander assembly nut.
    22.  
    23. Carefully slide the J 33049 into the engine block until the J 33049 expander assembly is positioned between the camshaft inner bearing bores.
    24.  

  4.  
  5. Install the NEW camshaft inner bearings #3 and #2.
    1. Install the NEW camshaft inner bearing #3 onto the J 33049 expander assembly.
    2.  
    3. Tighten the J 33049 expander assembly nut until snug.
    4.  
    5. Align the lubrication hole of the camshaft inner bearing #3 above the 3 o'clock position or the 9 o'clock position of the camshaft inner bearing bore #3 of the engine block.
    6.  
    7. Push the J 33049 guide cone into the camshaft front bearing bore #1 in order to align the J 33049.
    8.  
    9. Drive the camshaft inner bearing #3 into the camshaft inner bearing bore #3.
    10.  
    11. Loosen the J 33049 expander assembly nut.
    12.  
    13. Carefully slide the J 33049 until the J 33049 expander assembly is positioned between the camshaft inner bearing bore #2 and the camshaft outer bearing bore #1.
    14.  
    15. Install the NEW camshaft inner bearing #2 onto the J 33049 expander assembly.
    16.  
    17. Tighten the J 33049 expander assembly nut until snug.
    18.  
    19. Align the lubrication hole of the camshaft inner bearing #2 above the 3 o'clock position or the 9 o'clock position of the camshaft inner bearing bore #2 of the engine block.
    20.  
    21. Push the J 33049 guide cone into the camshaft front bearing bore #1 in order to align the J 33049.
    22.  
    23. Drive the camshaft inner bearing #2 into the camshaft inner bearing bore #2.
    24.  
    25. Loosen the J 33049 expander assembly nut.
    26.  

  6.  
  7. Carefully remove the J 33049 from the engine block.
  8.  

Inspection



Using solvent, degrease the camshaft and clean out all of the oil holes. Visually inspect the cam lobes and bearing journals for excessive wear. If a lobe is questionable, check all of the lobes as indicated. If a journal or lobe is worn, the camshaft MUST BE reground or replaced.


NOTE
If a journal is worn, there is a good chance that the bushings are worn and need replacement.

If the lobes and journals appear intact, place the front and rear journals in V-blocks and rest a dial indicator on the center journal. Rotate the camshaft to check the straightness. If deviation exceeds 0.001 in. (0.0254mm), replace the camshaft.

Check the camshaft lobes with a micrometer, by measuring the lobes from the nose to the base and again at 90° (see illustration). The lobe lift is determined by subtracting the second measurement from the first. If all of the exhaust and intake lobes are not identical, the camshaft must be reground or replaced.


NOTE
Camshaft lobe lift can also be measured with the shaft still installed.

To determine camshaft lobe wear, with the shaft still installed.

  1. Remove the rocker arm covers.
  2.  
  3. Loosen and reposition the rocker arms so the pushrods can be accessed.

    Click image to see an enlarged view

    Fig. Use a dial indicator to measure the camshaft for straightness (camshaft run-out)



    Click image to see an enlarged view

    Fig. Subtract measurement B from measurement A (width from height) in order to determine camshaft lobe lift



    Click image to see an enlarged view

    Fig. A dial gauge can be used to measure lobe lift with the camshaft installed

  4.  
  5. Mount a dial gauge so the plunger rests on the end of the pushrod (so it will read pushrod movement).
  6.  
  7. Turn the crankshaft slowly in the normal direction of rotation until the lifter is on the base of the camshaft lobe (the pushrod will not be at its lowest point of travel), then zero the gauge.
  8.  
  9. Rotate the crankshaft slowly until the pushrod moves to the fully raised position.
  10.  
  11. Compare the readings for each camshaft lobe (as shown by the dial indicator) with the specifications.
    NOTE
    Keep in mind that hydraulic lifters can allow for some camshaft lobe height loss. If a camshaft is close, but out of specification, verify that plunger movement is not responsible for the difference before replacing the shaft.

  12.  
  13. Reposition and install the rocker arms. For details, please refer to the procedure found earlier in this section.
  14.  
  15. Install the rocker arm covers.
  16.  

Removal & Installation



  1. Before servicing the vehicle, refer to the Precautions Section.
  2.  
  3. Properly relieve the fuel system pressure.
  4.  
  5. Drain the engine cooling system.
  6.  
  7. Discharge and recover the refrigerant from the air conditioning system.
  8.  
  9. Remove or disconnect the following:

    Negative battery cable
     
    Engine cover
     
    Air intake assembly
     
    Engine cooling fan and shroud
     
    Radiator hoses
     
    Transmission oil cooler lines
     
    Coolant recovery reservoir
     
    Grille
     
    Radiator
     
    A/C condenser
     
    Lower intake manifold
     
    Rocker arms and rocker arm supports
     
    Pushrods
     

  10.  
  11. Remove the bolts and valve lifter pushrod guide.
  12.  
  13. Remove the valve lifters.
  14.  
  15. Remove or disconnect the following:

    Timing chain
     
    Camshaft sprocket
     
    Balance shift drive gear, if equipped
     
    Thrust plate
     

  16.  
  17. Install three 5 / 16 x 4 inch bolts into the engine camshaft front bolt holes.
  18.  
  19. Using the bolts as a handle, carefully rotate and pull the camshaft out of the camshaft bearings.
    NOTE
    Take care not to damage the camshaft bearings when removing the camshaft.



    Click image to see an enlarged view

    Fig. Thread 3 long bolts into the camshaft to use as a handle, then withdraw it from the engine

  20.  

To install:

  1. Lubricate the camshaft journals with clean engine oil or a suitable pre-lube.
  2.  
  3. Install camshaft being extremely careful not to contact the bearings with the cam lobes.
  4.  
  5. Install or connect the following:

    Thrust plate. Torque the bolts to 106 inch lbs. (12 Nm).
     
    Balance shaft drive gear. Tighten the bolts to 15 ft. lbs. (20 Nm) plus 35 degrees.
     
    Camshaft sprocket
     
    Timing chain
     
    Valve lifters
     
    Valve lifter pushrod guide and tighten the bolts to 12 ft. lbs. (16 Nm)
     
    Pushrods
     
    Rocker arms
     
    Lower intake manifold assembly
     
    A/C condenser
     
    Radiator
     
    Grille
     
    Coolant recovery reservoir
     
    Transmission oil cooler lines
     
    Radiator hoses
     
    Engine cooling fan and shroud
     
    Air intake assembly
     
    Engine cover
     
    Negative battery cable
     

  6.  
  7. Refill the engine cooling system.
  8.  
  9. Start the engine and check for leaks.
  10.  

 
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