CTS 2006-2007, CTS-V 2005-2007, DTS 2006-2007

Camshaft, Rocker Arms & Lifters

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Inspection



2.8L & 3.6L Engine

WARNING
Wear safety glasses in order to avoid eye damage.

  1. Inspect the camshaft oil feed holes (1) to the camshaft position actuator for dirt, debris or blockage.
  2.  
  3. Inspect the threaded hole (2) for damage.
  4.  
  5. Inspect the camshaft position actuator locating notch (3) for damage or wear.
  6.  
  7. Inspect the camshaft sealing grooves (4) for damage.
  8.  
  9. Inspect the camshaft thrust surface (5) for damage.
  10.  
  11. Inspect the camshaft lobes (6) and journals (7) for the following conditions:
    1. Excessive scoring or pitting
    2.  
    3. Discoloration from overheating
    4.  
    5. Deformation from excessive wear, especially the camshaft lobes
    6.  

  12.  
  13. If any of the above conditions exist on the camshaft, replace the camshaft.

    Click image to see an enlarged view

    Fig. View of camshaft inspection points

  14.  
  15. With the camshaft in a suitable fixture, measure the camshaft for wear.
  16.  
  17. Measure the camshaft journals for diameter and out-of-round using an outside micrometer. Refer to Engine Mechanical Specifications.
    1. If the diameter is smaller than specifications, replace the camshaft.
    2.  
    3. If the out-of-round exceeds specifications, replace the camshaft.
    4.  

  18.  
  19. Measure the camshaft runout using the J 7872. Refer to Engine Mechanical Specifications.
  20.  
  21. Measure the camshaft thrust width for wear using a depth micrometer. Refer to Engine Mechanical Specifications.

    Click image to see an enlarged view

    Fig. View of camshaft thrust width location

  22.  
  23. Measure the camshaft thrust wall surface for runout using J 7872. Refer to Engine Mechanical Specifications.
  24.  
  25. If the camshaft is damaged or worn beyond specifications, replace the camshaft. No machining of the camshaft is allowed.

    Click image to see an enlarged view

    Fig. View of camshaft thrust wall surface being taken

  26.  
  27. Measure the camshaft lobes for wear using the J 7872.
  28.  
  29. Place the J 7872 with the indicator tip on the base circle (1) of the camshaft lobe.
    1. Place the J 7872 at zero.
    2.  
    3. Rotate the camshaft until the indicator tip is at the highest point (3) on the lobe. This reading is the lift of the camshaft lobe. Refer to Engine Mechanical Specifications.
    4.  
    5. If the indicated measurement is significantly lower than these specifications, replace the camshaft or engine performance will be reduced.

      Click image to see an enlarged view

      Fig. Camshaft lobe view

    6.  

  30.  

4.6L Engine

WARNING
Wear safety glasses in order to avoid eye damage.

  1. Clean the camshaft in solvent.
  2.  
  3. Dry the camshaft with compressed air.
  4.  
  5. Cover the camshafts with a clean oil soaked towel in order to prevent corrosion.
  6.  
  7. Inspect the camshaft sprocket locating pin (2) for damage or wear.
  8.  
  9. Inspect the threads (3) for the camshaft sprocket bolt.
  10.  
  11. Inspect the camshaft lobes (1) and journals (4) for the following conditions:
    1. Excessive scoring or pitting
    2.  
    3. Discoloration from overheating
    4.  
    5. Deformation from excessive wear, especially the camshaft lobes

      Click image to see an enlarged view

      Fig. View of camshaft inspection points

    6.  

  12.  
  13. Inspect the left intake camshaft for the following additional conditions:
    1. Excessive wear on the sealing surface (1) for the camshaft seal
    2.  
    3. Damage to the threads (2) for the water pump drive belt pulley bolt
    4.  

  14.  
  15. If any of the above conditions exist on the camshaft, replace the camshaft.

    Click image to see an enlarged view

    Fig. View of left intake camshaft inspection points

  16.  
  17. With the camshaft in a suitable fixture, measure the camshaft for wear.
  18.  
  19. Measure the camshaft journals for diameter and out-of-round using an outside micrometer.
    1. If the diameter is smaller than 1.061 inch (26.948 mm), replace the camshaft.
    2.  
    3. If the out-of-round exceeds 0.0009 inch (0.022 mm), replace the camshaft.

      Click image to see an enlarged view

      Fig. Checking camshaft journals

    4.  

  20.  
  21. Measure the camshaft runout using the J 7872 magnetic base dial indicator.
  22.  
  23. Measure the camshaft thrust wall width (1) for wear using an inside micrometer.
  24.  
  25. Measure the camshaft thrust wall surface (2) for runout using J 7872.
  26.  
  27. If the camshaft is damaged or worn beyond specifications, replace the camshaft. No machining of the camshaft is allowed.

    Click image to see an enlarged view

    Fig. View of camshaft thrust wall width (1) and wall surface (2)

  28.  
  29. Measure the camshaft lobes for wear using the J 7872.
  30.  
  31. Place the J 7872 with the indicator tip on the base circle (2) of the camshaft lobe.
    1. Place the J 7872 dial at zero.
    2.  
    3. Rotate the camshaft until the indicator tip is at the highest point on the lobe. This reading is the lift (1) of the camshaft lobe.
    4.  
    5. The specifications for lift are as follows:

      Intake camshaft: 6.154 mm (0.2423 in)
       
      Exhaust camshaft: 5.944 mm (0.2336 in)
       

    6.  

  32.  
  33. If the indicated measurement is significantly lower than these specifications, replace the camshaft or engine performance will be reduced.
  34.  


  35. Click image to see an enlarged view

    Fig. Camshaft lobe view, lift (1) base circle (2)

  36.  

5.7L & 6.0L Engines

WARNING
Wear safety glasses in order to avoid eye damage.

  1. Clean the components in solvent.
  2.  
  3. Dry the components with compressed air.
  4.  
  5. Inspect the camshaft bearing journals (1) for scoring or excessive wear.
  6.  
  7. Inspect the camshaft valve lifter lobes (2) for scoring or excessive wear.
  8.  
  9. Inspect the threaded bolt holes (3) in the front of the camshaft for damaged threads or debris.
  10.  
  11. Inspect the camshaft sprocket pin (204) for damage.
  12.  
  13. Inspect the camshaft retainer plate for wear or a damaged sealing gasket.
    NOTE
    If the camshaft retainer plate sealing gasket is not cut or damaged, it may be used again.



    Click image to see an enlarged view

    Fig. Camshaft inspection points

  14.  
  15. Inspect the camshaft bearings for proper fit in the engine block. Camshaft bearings have an interference fit to the engine block and should not be loose in the engine block bearing bores.
  16.  
  17. Inspect the camshaft bearings for excessive wear or scoring. Bearings with excessive scoring or wear must be replaced.
  18.  
  19. Using a micrometer, measure the camshaft journals for wear and out-of-round.
    1. If the camshaft bearing journals are greater than 0.001 inch (0.025 mm) out-of-round, replace the camshaft.
    2.  
    3. If the camshaft bearing journal diameter is less than 2.164 inch (54.99 mm), replace the camshaft.

      Click image to see an enlarged view

      Fig. Checking camshaft journals

    4.  

  20.  
  21. Using a micrometer, measure the camshaft lobes for wear. Refer to Engine Mechanical Specifications.

    Click image to see an enlarged view

    Fig. Checking camshaft lobes

  22.  
  23. Measure the camshaft runout.
    1. Mount the camshaft in wooden V-blocks or between centers on a fixture.
    2.  
    3. Using the J 7872, measure the runout of the intermediate camshaft bearing journals.
    4.  
    5. If camshaft runout exceeds 0.002 inch (0.05 mm), the camshaft is bent and should be replaced.

      Click image to see an enlarged view

      Fig. Measuring the runout of the intermediate camshaft bearing journals

    6.  

  24.  

Measuring camshaft lobe lift is a procedure used to determine if the camshaft lobes have worn. This test is to be performed prior to engine disassembly and with the camshaft and valve train components installed in the engine.

  1. Using the J 8520, measure camshaft lobe lift.
  2.  
  3. Remove the valve rocker arms and bolts.
  4.  
  5. Install the dial indicator mounting stud into the valve rocker arm bolt hole.
  6.  
  7. Assemble the components of the J 8520 and position onto the stud.
  8.  
  9. Position the shaft of the dial indicator onto the end of the pushrod.
  10.  
  11. Rotate the face of the dial indicator to zero.
  12.  
  13. Slowly rotate the crankshaft clockwise, until the dial indicator obtains its highest and lowest readings.
  14.  
  15. Compare the total to specifications. Refer to Engine Mechanical Specifications.

    Click image to see an enlarged view

    Fig. Using the J 8520 to measure camshaft lobe lift

  16.  

Removal & Installation



2.8L & 3.6L Engines
  1. Before servicing the vehicle, refer to the Precautions Section.
  2.  
  3. Remove or disconnect the following:

    Negative battery cable
     
    Intake manifold assembly
     
    Ignition coil electrical connectors
     
    Wiring harnesses and wiring conduit retainers from the camshaft cover
     
    Ignition coils
     
    Camshaft cover
     
    Camshaft position (CMP) sensors
     
    CMP actuator solenoid
     
    Crankshaft pulley
     

  4.  
  5. Rotate the crankshaft until the camshafts are in the neutral (low) position. The camshaft flats will be parallel with the camshaft cover rail.
  6.  
  7. Loosen the camshaft position actuator bolt.
  8.  
  9. Remove the front cover.
    NOTE
    Do not remove the bolt at this time.

  10.  
  11. Install the Timing Chain Retention Tool EN-46108 to retain the timing chain.
  12.  
  13. Matchmark the timing chain on the camshaft position actuators.
  14.  
  15. Remove or disconnect the following:

    CMP actuator bolt
     
    Camshaft bearing caps
     
    Camshafts
     

  16.  
  17. Remove the rocker arms.
  18.  
  19. Clean and inspect the camshaft(s) and the rocker arm(s). Repair or replace as necessary.

    Click image to see an enlarged view

    Fig. Installing camshaft retention tool EN-46108 and ensure the tips are fully engaged on the timing chain (3 and 4)-2.8L and 3.6L



    Click image to see an enlarged view

    Fig. Camshaft bearing cap torque sequence-2.8L and 3.6L

  20.  

To install:

  1. Apply a liberal amount of camshaft lubricant to the pivot pocket, roller and valve slot (3) areas of the camshaft followers.
    NOTE
    The follower must be positioned squarely on the valve tip so that the full width of the roller will completely contact the camshaft lobe. If the followers are being reused you must put them back in their original location.

  2.  
  3. Place the camshaft followers in position on the valve tip and Stationary Hydraulic Lash Adjuster (SHLA).
  4.  
  5. The rounded head end of the follower goes on the SHLA while the flat end goes on the valve tip.
  6.  
  7. Clean the camshaft journals and carriers with a clean, lint-free cloth.
  8.  
  9. Lubricate the camshaft lobes, lifters and bearing journals with camshaft lubricant.
  10.  
  11. Position the camshaft lobes in a neutral position with the flats on the back of the camshafts up and parallel with the left cylinder head camshaft cover rail.
    WARNING
    The bearing caps must be installed in their original positions.

  12.  
  13. Install the camshaft bearing thrust cap in the first journal of the cylinder head.
  14.  
  15. Install the remaining bearing caps with their orientation mark toward the center of the cylinder head.
  16.  
  17. Hand start all the camshaft bearing cap bolts.
  18.  
  19. Tighten the bearing cap bolts in sequence as follows:
    1. Step 1: Tighten all bolts to 89 inch lbs. (10 Nm).
    2.  
    3. Step 2: Loosen the center intake camshaft bearing cap bolts (1,2) and center exhaust camshaft bearing cap (3.4).
    4.  
    5. Step 3: Retighten center camshaft bearing cap bolts to 89 inch lbs. (10 Nm).
    6.  

  20.  
  21. Remove the Timing chain retention tool EN-46108.
  22.  
  23. Install or connect the following:

    CMP actuators. Tighten the bolts to 43 ft. lbs. (58 Nm).
     
    Front cover
     
    CMP actuator solenoid
     
    CMP sensors
     
    Crankshaft pulley
     
    Camshaft cover
     
    Ignition coils
     
    Wiring harnesses and conduit retainers to the camshaft cover
     
    Ignition coil electrical connectors
     
    Intake manifold
     
    Negative battery cable
     

  24.  
  25. Start the engine and verify proper operation.
  26.  

4.6L Engine
  1. Before servicing the vehicle, refer to the Precautions Section.
  2.  
  3. Remove the camshaft cover
  4.  
  5. Rotate the crankshaft to TDC of the no. 1 cylinders compression stroke, both camshaft sprocket drive pins should be at the top of their rotation.

    Click image to see an enlarged view

    Fig. Camshaft sprocket drive pins at the top of their rotation

  6.  
  7. Install the J 44212 holding tool over the camshafts.

    Click image to see an enlarged view

    Fig. Camshaft holding tool J 44212

  8.  
  9. Use a paint stick to create a mark  (1) on the timing chain link adjacent to each camshaft sprocket timing mark (2, 3).

    Click image to see an enlarged view

    Fig. Paint mark (1) timing marks (2) and (3)

  10.  
  11. Install both EN 46327 camshaft sprocket and chain holding tools  (1) to the engine using the following step:
    1. Rotate the wing nut (2) of the EN 46327 (3) to the top of its travel.

      Click image to see an enlarged view

      Fig. EN 46327 holding tools shown

    2.  

  12.  
  13. Position the bottom retention tool on the cylinder head with the V-notch of the block (1) adjacent to the left exhaust camshaft sprocket and chain.
  14.  
  15. Insert the hook end (2) into a secondary timing chain link as shown.

    Click image to see an enlarged view

    Fig. Holding tool installed into timing chain

  16.  
  17. Rotate the wing nut until it contacts the retention tool block (1). DO NOT tighten the wing nut at this time.
  18.  
  19. Rotate the wing nut (2) of the EN 46327 (4) to the top of its travel.
  20.  
  21. Position the top retention tool on the cylinder head with the V-notch of the block (1) adjacent to the left intake camshaft sprocket and chain.
  22.  
  23. Insert the hook end (2) into a secondary timing chain link as shown.
  24.  
  25. Rotate the wing nut until it contacts the retention tool block (1). Alternately tighten both wing nuts to retain the chain.
  26.  
  27. Use an open wrench on the hex cast into the camshafts in order to prevent the camshafts from rotating when removing the camshaft sprocket bolts.
  28.  
  29. Remove the camshaft sprocket bolts
  30.  
  31. Remove the camshaft sprockets.
  32.  
  33. Alternately loosen the camshaft bearing cap bolts a few turns at a time until all valve spring pressure has been released.
  34.  
  35. Remove the camshaft bearing caps.
  36.  
  37. Remove the J 44212 from the camshafts.
  38.  
  39. Remove the camshafts.

    Click image to see an enlarged view

    Fig. Camshaft removal

  40.  
  41. Remove the camshaft followers.
  42.  
  43. Remove the Stationary Hydraulic Lash Adjusters (SHLA) from the bores.
  44.  

To install:

  1. Fill the stationary hydraulic lash adjuster (SHLA) with clean engine oil.
  2.  
  3. Install the new SHLA's into the bores.
  4.  
  5. Apply a liberal amount of lubricant to the roller pivot pocket and valve slot areas of the camshaft followers.
    WARNING
    The follower must be positioned squarely on the valve tip so that the full width of the roller will completely contact the camshaft lobe. If the followers are being reused you must put them back in their original location.

  6.  
  7. Place the camshaft followers in position on the valve tip and the SHLA. The rounded head of the follower goes on the SHLA, while the flat end goes on the valve tip.
  8.  
  9. Clean the camshaft carriers with a clean, lint-free cloth.
  10.  
  11. Apply a liberal amount of lubricant to the camshaft carriers, camshaft lobes and the camshaft journals. 
  12.  
  13. Place the camshaft in the camshaft carriers with the camshaft sprocket drive pins near the top of their rotation and the camshaft lobes in a neutral position.
  14.  
  15. The camshafts can be identified by a stamping near the rear journal. For example: L-EXH is defined as Left bank Exhaust
  16.  
  17. Observe the markings on the camshaft bearing caps. Each camshaft bearing cap is marked in order to identify its location.
  18.  
  19. The markings have the following meanings:

    The arrow should point to the front of the engine.
     
    The number indicates the position from the front of the engine.
     
    The "E" indicates the exhaust camshaft.
     
    The "I" indicates the Intake camshaft.
     

  20.  
  21. Apply a liberal amount of lubricant to the camshaft bearing caps.
  22.  
  23. Install the camshaft bearing caps according to the identification marks.
  24.  
  25. Install the camshaft bearing cap bolts in sequence and tighten as follows:
    1. Alternately hand tighten the camshaft bearing cap bolts a few turns at a time until all caps are fully seated.
    2.  
    3. Tighten the camshaft bearing cap bolts to 44 inch lbs. (5 Nm).
    4.  
    5. Tighten the camshaft bearing cap bolts an additional 30 degrees using the J 45059 angle meter.

      Click image to see an enlarged view

      Fig. 4.6L-Camshaft bearing cap bolts tightening sequence

    6.  

  26.  
  27. Align the camshafts.
  28.  
  29. Install the J 44212 over the camshafts.
  30.  
  31. Install the intake and exhaust camshaft sprockets aligning the paint marks made during disassembly. Ensure that the camshaft sprockets align with the pins of the camshafts.
  32.  
  33. Use an open wrench on the hex cast into the camshafts in order to prevent the camshafts from rotating when tightening the camshaft sprocket bolts.
  34.  
  35. Install the camshaft sprocket bolts and tighten to 89 ft. lbs. (120 Nm).
  36.  
  37. Remove the EN 46327 holding tool.
  38.  
  39. Verify the camshaft sprocket alignment.
  40.  
  41. Remove the J 44212 from the camshafts.
  42.  
  43. Install the left camshaft cover.
  44.  

5.7L & 6.0L Engines
  1. Before servicing the vehicle, refer to the precautions in the beginning of this engine.
  2.  
  3. Remove or disconnect the following:

    Engine assembly
     
    Intake manifold
     
    Left cylinder head
     
    Right cylinder head
     
    Camshaft position (CMP) sensor
     
    Front cover
     
    Valve lifter guide bolts
     
    Valve lifters and guides
     

  4.  
  5. Rotate the crankshaft in order to align the timing marks.
  6.  
  7. Remove the camshaft sprocket bolts.
  8.  
  9. Remove the timing chain from the camshaft sprocket, and allow the chain to rest on the crankshaft sprocket.
  10.  
  11. Remove the camshaft retainer bolts and retainer.
  12.  
  13. Install 3 M8 - 4 inch (100 mm) in the camshaft front bolt holes.
  14.  
  15. Using the bolts as a handle, rotate and pull the camshaft out of the engine block.

    Click image to see an enlarged view

    Fig. Removing the camshaft using the bolts as a handle-5.7L

  16.  

To install:

  1. Lubricate the camshaft journals and the bearings with clean engine oil.
  2.  
  3. Install 3 M8 - 4 inch (100 mm) in the camshaft front bolt holes.
  4.  
  5. Using the bolts as a handle, carefully install the camshaft into the engine block.
  6.  
  7. Remove the 3 bolts from the front of the camshaft.
  8.  
  9. Install the camshaft retainer. Tighten the bolts as follows:
    1. Hex head bolts to 18 ft. lbs (25 Nm)
    2.  
    3. TORX® head bolts to 11 ft. lbs. (15 Nm)
    4.  

  10.  
  11. CMP sensor. Tighten the bolt to 18 ft. lbs (25 Nm).
    NOTE
    Lubricate the sensor O-ring seal with clean engine oil.

  12.  
  13. Install or connect the following:

    Timing chain to the camshaft sprocket
     
    Camshaft sprocket and bolts to the camshaft. Tighten the bolts to 26 ft. lbs. (35 Nm).
     
    Valve lifters, valve guides and guide bolts
     
    Front cover
     
    CMP sensor
     
    Right cylinder head
     
    Left cylinder head
     
    Intake manifold
     
    Engine assembly
     

  14.  
  15. Start the engine and check for leaks.
  16.  

 
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