Silverado 2008

Timing Chain And Sprockets

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Removal & Installation



4.3L Engines

Specific to:

Chevrolet Silverado 1500 2008

  1. Before servicing the vehicle, refer to the Precautions Section.
  2.  
  3. Disconnect the negative battery cable.
  4.  
  5. Drain the cooling system. Properly dispose of used coolant.
  6.  
  7. Remove the water pump.
  8.  
  9. Remove the crankshaft balancer.
  10.  
  11. Remove the oil pan.
  12.  
  13. Remove the engine skid plates, if equipped.
  14.  
  15. Remove the engine wiring harness from the front cover.
  16.  
  17. Disconnect the Crankshaft Position (CKP) sensor electrical connector, if equipped.
  18.  
  19. Remove the CKP sensor and discard the O-ring.
  20.  
  21. Disconnect the engine wiring harness connector from the Camshaft Position (CMP) sensor.
  22.  
  23. Remove the CMP sensor.
  24.  
  25. Remove the front cover retaining bolts.
  26.  
  27. Remove the front cover from the engine.
    NOTE
    Do not reuse the front cover. It is a composite cover and must be replaced with a new cover.



    Click image to see an enlarged view

    Fig. Timing cover and related components-4.3L engines

  28.  
  29. Rotate the crankshaft until the timing marks on the camshaft and crankshaft sprockets are in proper alignment. This will put no. 4 cylinder at TDC.
  30.  
  31. Unsnap the timing chain tensioner shoe from the pin.
  32.  
  33. Remove or disconnect the following:
    NOTE
    The camshaft sprocket (located by a dowel) is lightly pressed onto the camshaft and should come off easily. The chain comes off with the camshaft sprocket.



    Camshaft sprocket-to-camshaft nut and/or bolts
     
    Camshaft sprocket (along with the timing chain), if the sprocket is difficult to remove, use a plastic mallet to bump the sprocket from the camshaft.

    Click image to see an enlarged view

    Fig. Timing mark alignment for timing chain removal and installation-4.3L engines

     

  34.  
  35. If necessary use J-5825-A, or equivalent, crankshaft sprocket removal tool to free the timing sprocket from the crankshaft.
  36.  
  37. Remove the crankshaft balancer key.
  38.  
  39. If necessary, remove the timing chain tensioner bracket bolt and bracket.
  40.  

To install:


NOTE
Be sure to use new fasteners, as required.

  1. Inspect the timing chain and the timing sprockets for wear or damage, replace the damaged parts as necessary.
  2.  
  3. Clean the gasket mounting surfaces of all remaining traces of old gasket.
    NOTE
    During installation, coat the thrust surfaces lightly with Molykote® or equivalent pre-lube.

  4.  
  5. If necessary, install the timing chain tensioner bracket and bolt and tighten to 106 inch lbs. (12 Nm).
  6.  
  7. Install the key into the crankshaft keyway. The crankshaft balancer key should be parallel to the crankshaft or with a slight incline.
  8.  
  9. Install or connect the following:

    Crankshaft sprocket onto the crankshaft, use tool J-5590, crankshaft sprocket installation tool, and a hammer, without disturbing the position of the engine.
     
    Timing chain, arrange the camshaft sprocket in such a way that the timing marks will align between the shaft centers and the camshaft locating dowel will enter the dowel hole in the cam sprocket.
     
    Cam sprocket, with the chain mounted under it in position on the front of the camshaft. Torque the camshaft sprocket-to-camshaft retainer bolts to 18 ft. lbs. (25 Nm).
     

  10.  
  11. Install the timing chain tensioner shoe onto the bracket and position the top of the shoe under the tab at the top of the bracket.
  12.  
  13. With the timing chain installed, turn the crankshaft 2 complete revolutions, then check to make certain that the timing marks are in correct alignment between the shaft centers.
  14.  
  15. Install the new cover to the engine. Tighten the retaining bolts to 106 inch lbs. (12 Nm).
  16.  
  17. Using a new O-ring, lubricated with clean engine oil, install the CMP sensor. Tighten the retaining bolt to 89 inch lbs. (10 Nm).
  18.  
  19. Using a new O-ring, lubricated with clean engine oil, install the CKP sensor. Tighten the retaining bolt to 71 inch lbs. (8 Nm).
    NOTE
    Be sure that the sensor is correctly seated before tightening the retaining bolt.

  20.  
  21. Continue the installation in the reverse order of the removal procedure.
  22.  
  23. Start the engine and check for proper operation. Correct as required.
  24.  
  25. Check for leaks, correct as required.
  26.  

4.8L, 5.3L & 6.0L Engines

Specific to:

Chevrolet Silverado 1500 2008

  1. Before servicing the vehicle, refer to the Precautions Section.
  2.  
  3. Disconnect the negative battery cable.
  4.  
  5. Drain the cooling system. Properly dispose of used coolant.
  6.  
  7. Remove the water pump.
  8.  
  9. Remove the crankshaft balancer.
  10.  
  11. Remove the oil pan to front cover bolts.
  12.  
  13. Remove the front cover retaining bolts.
  14.  
  15. Remove the front cover. Discard the gasket. Remove the oil seal.
  16.  
  17. Remove the starter.

    Click image to see an enlarged view

    Fig. Front cover and related components-4.8L and 5.3L engines



    Click image to see an enlarged view

    Fig. Front cover and related components-6.0L engines



    Click image to see an enlarged view

    Fig. Front cover and gasket-4.8L, 5.3L & 6.0L engines

  18.  
  19. Remove the oil pump.
  20.  
  21. Rotate the crankshaft until the timing marks on the crankshaft and the camshaft sprockets are aligned.
    NOTE
    Do not turn the crankshaft assembly after the timing chain has been removed in order to prevent damage to the piston assemblies or the valves.

  22.  
  23. Remove or disconnect the following:

    Click image to see an enlarged view

    Fig. Sprocket and chain removal-4.8L, 5.3L & 6.0L engines



    Camshaft sprocket bolts
     
    Camshaft sprocket and timing chain
     
    Crankshaft sprocket
     
    Crankshaft sprocket key
     

  24.  

To install:


NOTE
Be sure to use new fasteners, as required.



Click image to see an enlarged view

Fig. Crankshaft sprocket installation-4.8L, 5.3L & 6.0L engines

  1. Install or connect the following:

    Key into the crankshaft keyway

    Click image to see an enlarged view

    Fig. Crankshaft keyway (view one)-4.8L, 5.3L & 6.0L engines



    Click image to see an enlarged view

    Fig. Crankshaft keyway (view two)-4.8L, 5.3L & 6.0L engines

     
    Crankshaft sprocket onto the front of the crankshaft. Align the crankshaft key with the crankshaft sprocket keyway. Rotate the crankshaft sprocket until the alignment mark is in the 12 o'clock position.
     
    Camshaft sprocket and timing chain. Locate the camshaft sprocket alignment mark in the 6 o'clock position.
     
    Camshaft sprocket bolts and tighten to 26 ft. lbs. (35 Nm)

    Click image to see an enlarged view

    Fig. Timing mark alignment-4.8L, 5.3L & 6.0L engines

     

  2.  
  3. Install the oil pump.
  4.  
  5. Apply a 0.20 inch of sealant to the engine block and oil pan junction. Be sure to use the proper grade and type sealant.
  6.  
  7. Install the new cover to the engine. Tighten the retaining bolts until they are snug.
  8.  
  9. Install the cover to oil pan bolts. Tighten until snug.
  10.  
  11. Align the tapered legs of the alignment tool J-41476 or equivalent, with the machined alignment surfaces on the front cover.

    Click image to see an enlarged view

    Fig. Timing cover alignment tool installation-4.8L, 5.3L & 6.0L engines

  12.  
  13. Install the balancer bolt until snug.
  14.  
  15. Tighten the oil pan front cover bolts to 18 ft. lbs. (25 Nm). Tighten the timing cover bolts to 18 ft. lbs. (25 Nm).
  16.  
  17. Remove the alignment tool.
  18.  
  19. Install a new front cover seal, using the proper seal installation tool.
  20.  
  21. Continue the installation in the reverse order of the removal procedure.
  22.  
  23. Start the engine and check for proper operation. Correct as required.
  24.  
  25. Check for leaks, correct as required.
  26.  

 
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