Infinity_QX56_2004-2005

Camshaft & Valve Lifters

Print

Inspection



Runout
  1. Before servicing the vehicle, refer to the Precautions Section.
  2.  
  3. Remove the camshafts.
  4.  
  5. Using a V-block on a precise flat table, support the No. 2 and 4 journals of the camshaft.
    NOTE
    Do not support journal No. 1 as it has a different diameter than the other locations.

  6.  
  7. Set the dial indicator to No. 3 journal.
  8.  
  9. Turn the camshaft to one direction by hand and measure the camshaft runout.
  10.  
  11. Runout should measure less than 0.0008 inches (0.02 mm).
  12.  
  13. Camshaft should be replaced if it exceeds the limit.
  14.  

Cam Height
  1. Before servicing the vehicle, refer to the Precautions Section.
  2.  
  3. Remove the camshafts.
  4.  
  5. Measure the cam height with a micrometer.
  6.  
  7. The intake and exhaust camshaft should measure between 1.7506-1.7581 inches (44.465-44.655 mm).
  8.  
  9. Camshaft should be replaced if it exceeds the limit.
  10.  

Journal Oil Clearance
  1. Before servicing the vehicle, refer to the Precautions Section.
  2.  
  3. Remove the camshafts.
  4.  
  5. Measure the outer diameter of camshaft journal with micrometer and record the result.
  6.  
  7. Reinstall the camshaft bearing caps in accordance to the installation procedure.
  8.  
  9. Measure the inner diameter of the camshaft bracket (A) with a bore gauge and record the result.
  10.  
  11. Subtract the camshaft journal diameter from the camshaft bracket inner diameter. The difference should measure between 0.0012-0.0027 inches (0.030-0.068 mm).
  12.  
  13. The camshaft or camshaft bracket should be replaced if it exceeds the limit.
    NOTE
    The camshaft bracket cannot be replaced as an individual part, because it is machined together with the cylinder head. The entire cylinder head assembly must be replaced.



    Click image to see an enlarged view

    Fig. Measuring the journal bore for oil clearance

  14.  

End Play
  1. Before servicing the vehicle, refer to the Precautions Section.
  2.  
  3. Install a dial indicator in the thrust direction on the front end of the camshaft. Measure the end play of the dial indicator when the camshaft is moved back and forth. The dial indicator should measure between 0.0045-0.0074 inches (0.115-0.188 mm).
  4.  
  5. Measure the No. 1 journal as shown. The distance (A) should be 1.2008-1.2027 inches (30.500-30.548 mm).
  6.  
  7. Measure the No. 1 journal bearing as shown. The distance (B) should be 1.1953-1.1963 inches (30.360-30.385 mm).
  8.  
  9. Replace either the camshaft or cylinder head assembly if the measurement is exceeded.

    Click image to see an enlarged view

    Fig. Measuring for camshaft endplay

  10.  

Removal & Installation



  1. Before servicing the vehicle, refer to the Precautions Section.
  2.  
  3. Remove or disconnect the following:

    Negative battery cable
     
    Engine cover
     
    Air intake assembly
     
    Engine wiring harnesses on rocker cover
     
    Throttle control actuator
     
    Ignition coil
     
    PCV hose from PCV valve
     

  4.  
  5. Remove rocker cover, loosening the bolts in the reverse order.

    Click image to see an enlarged view

    Fig. Exploded view of the rocker cover assembly



    Click image to see an enlarged view

    Fig. Rocker cover torque sequence

  6.  
  7. Turn the crankshaft until the No. 1 cylinder is set at Top Dead Center (TDC).
  8.  
  9. Remove timing chain case covers.
  10.  
  11. Matchmark the timing chain, aligning with the camshaft sprocket marks.
  12.  
  13. Remove chain tensioner from left bank as follows:
    1. Squeeze end clips and push plunger into tensioner body.
    2.  
    3. Secure plunger using stopper pin.
    4.  
    5. Remove the chain tensioner.
    6.  

  14.  
  15. Remove the chain tensioner from right bank as follows:
    1. Remove the chain tensioner cover using special tool J-37228.
    2.  
    3. Squeeze end clips and push plunger into tensioner body.
    4.  
    5. Secure plunger using stopper pin.
    6.  
    7. Remove the chain tensioner.
    8.  

  16.  
  17. With camshaft locked with a wrench, loosen bolts to remove camshaft sprocket.
  18.  
  19. Remove front cover bolts.
  20.  
  21. Remove camshaft brackets, removing bolts in reverse order shown in figure.
  22.  
  23. Remove camshaft.
  24.  
  25. Remove valve lifters.
    NOTE
    Matchmark the drivetrain components so each part can be reinstalled in its original position.

  26.  

To install:

  1. Install valve lifters.
  2.  
  3. Install camshaft, refer to table for correct placement.

    Click image to see an enlarged view

    Fig. Camshaft installation markings

  4.  
  5. Install camshaft brackets as follows:
    1. Refer to location mark on upper surface of bracket.
    2.  
    3. Installation mark should be correctly read when viewed from intake side.
    4.  

  6.  
  7. Install camshaft bracket #1 as follows:
    1. Apply liquid gasket to bracket and backside of front cover as shown in figure.
    2.  
    3. Carefully position and mount camshaft bracket #1.
    4.  
    5. Temporarily tighten front cover bolts
    6.  

  8.  
  9. Tighten fixing bolts for camshaft brackets as follows:
    1. Step 1: Bolts 9-12: 17 in. lbs. (1.9 Nm)
    2.  
    3. Step 2: Bolts 1-8: 17 in. lbs. (1.9 Nm)
    4.  
    5. Step 3: All bolts: 52 in. lbs. (5.9 Nm)
    6.  
    7. Step 4: All bolts: 92 in. lbs. (10 Nm)

      Click image to see an enlarged view

      Fig. Gasket application for camshaft bracket



      Click image to see an enlarged view

      Fig. Camshaft bracket installation markings



      Click image to see an enlarged view

      Fig. Camshaft bracket torque sequence

    8.  

  10.  
  11. Tighten front cover bolts to 8 ft. lbs. (11 Nm)
  12.  
  13. Install camshaft sprocket as follows:
    1. Install camshaft sprocket aligning matchmarks with timing chain. Align camshaft sprocket key groove with dowel pin on camshaft front edge.
    2.  
    3. Temporarily tighten bolts.
    4.  
    5. Lock the camshaft with a wrench and tighten the bolts.

      Click image to see an enlarged view

      Fig. Camshaft installation markings

    6.  

  14.  
  15. Install chain tensioner as shown:
    1. Install chain tensioner, compress plunger and hold with stopper pin.
    2.  
    3. Tighten chain tensioner bolts to 61 in. lbs. (7 Nm)
    4.  
    5. Remove stopper pin, release plunger and apply tension to timing chain.
    6.  
    7. Install chain tensioner front cover (Right-hand bank only) and tighten bolts to 80 in. lbs. (9 Nm).
    8.  

  16.  
  17. Install or connect the following:

    Timing chain cover
     
    Rocker cover.
     
    PCV hose
     
    Ignition coil
     
    Throttle control actuator
     
    Engine wiring harnesses on rocker cover
     
    Air intake assembly
     
    Engine cover
     
    Negative battery cable
     

  18.  
  19. Start the engine and check for leaks.
  20.  

 
label.common.footer.alt.autozoneLogo