Escalade, Suburban 1500 & 2500, Tahoe, Yukon, Yukon XL 1500 & 2500 (2006-2007), Yukon Denali and Yukon Denali XL (2005-2006)

Camshaft, Bearings & Lifters

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Bearing Replacement



If excessive camshaft wear is found, or if the engine is completely rebuilt, the camshaft bearings should be replaced.


NOTE
The front and rear bearings should be removed last, and installed first. Those bearings act as guides for the other bearings and pilot.

  1. Remove the engine.
  2.  
  3. Drive the camshaft rear plug from the block.
  4.  
  5. Assemble the removal puller with its shoulder on the bearing to be removed. Gradually tighten the puller nut until the bearing is removed.
  6.  
  7. Remove the remaining bearings, leaving the front and rear for last. To remove these, reverse the position of the puller, so as to pull the bearings towards the center of the block. Leave the tool in this position, pilot the new front and rear bearings on the installer, and pull them into position.

    Click image to see an enlarged view

    Fig. Removing the camshaft bearings



    Click image to see an enlarged view

    Fig. Replacing the inner camshaft bearing



    Click image to see an enlarged view

    Fig. Installing the outer camshaft bearing



    Click image to see an enlarged view

    Fig. Make this simple tool to check camshaft bearing oil hole alignment

  8.  
  9. Return the puller to its original position and pull the remaining bearings into position.
    NOTE
    You must make sure that the oil holes of the bearings and block align when installing the bearings. If they don't align, the camshaft will not get proper lubrication and may seize or at least be seriously damaged. To check for correct oil hole alignment, use a piece of brass rod with a 90° bend in the end as shown in the illustration. Check all oil hole openings. The wire must enter each hole, or the hole is not properly aligned.

  10.  
  11. Replace the camshaft rear plug, and stake it into position. On the Diesel, coat the outer diameter of the new plug with GM sealant #1052080 or equivalent, and install it flush to 1 / 32 in. (0.794mm) deep.
  12.  

Inspection



Camshaft
End Play

After the camshaft has been installed, end-play should be checked. The camshaft sprocket should be installed on the cam. Use a dial gauge to check the end-play, by moving the camshaft forward and backward. Refer to the Camshaft Specifications chart.

Click image to see an enlarged view

Fig. Checking camshaft end-play

Lobe Height

Use a micrometer to check camshaft (lobe) height, making sure the anvil and the spindle of the micrometer are positioned directly on the heel and tip of the camshaft lobe as shown in the accompanying illustration. Refer to the Camshaft Specifications chart.

Click image to see an enlarged view

Fig. Checking camshaft lobe height



Click image to see an enlarged view

Fig. Checking camshaft journal diameter

Runout

Camshaft run-out should be checked when the camshaft has been removed from the engine. An accurate dial indicator is needed for this procedure. If the run-out exceeds the limit replace the camshaft. Refer to the Camshaft Specifications chart.

Click image to see an enlarged view

Fig. Checking camshaft run-out

Removal & Installation



4.8L, 5.3L, 6.0L & 6.2L Engines
  1. Raise the hood to the servicing position and secure it. Move the hood hinge bolt to hold the hood in the servicing position.
  2.  
  3. Remove or disconnect the following:

    Battery negative cable
     
    Coolant
     
    Upper and lower radiator hoses from the engine
     
    Air cleaner duct from the engine
     
    A/C condenser mounting bolts, if equipped
     
    Radiator support and radiator
     
    Engine cooling fan
     
    Drive belt
     
    A/C drive belt, if equipped
     
    Engine sight shield
     
    Electrical wiring harness from the thermostat housing
     
    Water pump

    Click image to see an enlarged view

    Fig. Camshaft sensor removal-4.8L, 5.3L, 6.0L and 6.2L engines

     

  4.  
  5. Raise the vehicle.

    Starter motor
     
    Right side closeout cover and bolt
     
    Crankshaft balancer
     
    Engine oil pan
     
    Engine front cover
     
    Cylinder heads from the engine
     
    Valve lifters from the engine

    Click image to see an enlarged view

    Fig. Camshaft retainer removal-4.8L, 5.3L, 6.0L and 6.2L engines

     

  6.  
  7. Align the timing marks on the camshaft and crankshaft sprockets. Make sure that the number 1 piston is in the firing position.
    NOTE
    All camshaft journals are the same diameter, so care must be used in removing or installing the camshaft to avoid damage to the camshaft bearings.



    Camshaft sprocket
     
    Camshaft sensor bolt and sensor
     
    Camshaft retainer bolts and retainer
     

  8.  
  9. Install the three M8-1.25 x 100 mm bolts in the camshaft front bolt holes. Using the bolts as a handle, carefully rotate and pull the camshaft out of the engine block. Remove the bolts from the front of the camshaft.
  10.  
  11. Clean and inspect all sealing surfaces.
  12.  

To install:


NOTE
If camshaft replacement is required, the valve lifters must also be replaced.

  1. Lubricate the camshaft journals and the bearings with clean engine oil. Install three M8-1.25 x 100 mm (M8-1.25 x 4.0 in) bolts into the camshaft front bolt holes.
    NOTE
    All camshaft journals are the same diameter, so care must be used in removing or installing the camshaft to avoid damage to the camshaft bearings.

  2.  
  3. Using the bolts as a handle, carefully install the camshaft into the engine block. Remove the three bolts from the front of the camshaft.
    NOTE
    Install the retainer plate with the sealing gasket facing the engine block. The gasket surface on the engine block should be clean and free of dirt or debris.

  4.  
  5. Install or connect the following:

    Camshaft retainer and the bolts. Tighten the camshaft retainer bolts to 18 ft. lbs. (25 Nm).
     

  6.  
  7. Inspect the camshaft sensor O-ring seal. If the O-ring seal is not cut or damaged, it may be reused. Lubricate the O-ring seal with clean engine oil.

    Camshaft sensor and bolt. Tighten the bolt to 18 ft. lbs. (25 Nm).
     
    Camshaft sprocket and timing chain
     
    Valve lifters
     
    Cylinder heads
     
    Engine front cover to the engine
     
    Oil pan
     
    Right side closeout cover
     
    Starter motor
     
    Crankshaft balancer to the crankshaft
     
    Water pump
     
    Electrical wiring harness to the thermostat housing
     
    A/C drive belt, if equipped
     
    Drive belt
     
    Engine sight shield
     
    Radiator support and radiator
     
    A/C condenser mounting bolts
     
    Engine cooling fan
     
    Air cleaner duct
     
    Negative battery cable
     

  8.  

8.1L Engine
  1. Properly discharge the air conditioning system.
  2.  
  3. Remove or disconnect the following:
    NOTE
    If any lifters are stuck in their bores, use a suitable valve lifter to remove them.


    WARNING
    All of the cam journals are the same size so be very careful when removing and installing the camshaft that you do not damage the bearings.



    Grille
     
    A/C condenser
     
    Intake manifold
     
    Rocker arms and pushrods
     
    Valve lifter guide retainer bolts and retainer
     
    Valve lifter guides, keeping them in proper order for reassembly
     
    Valve lifters
     
    Timing chain and sprocket
     
    Camshaft retaining bolts
     
    Camshaft retainer
     

  4.  
  5. Install three 8-1.25 x 100mm bolts in the holes in the front of the camshaft and carefully pull the camshaft from the block.

    Click image to see an enlarged view

    Fig. Use the 3 bolts as a handle to carefully remove and install the camshaft-8.1L engines

  6.  
  7. Remove the bolts from the front of the camshaft.
  8.  
  9. Clean and inspect the camshaft for damage.
  10.  

To install:

  1. Liberally coat camshaft and bearings with heavy engine oil or engine assembly lubricant.
  2.  
  3. Install the camshaft, using the 3 bolts threaded into the camshaft bolt holes as a handle, then remove the bolts.
    NOTE
    If a new camshaft is installed, you MUST install new valve lifters.

  4.  
  5. Install or connect the following:

    Camshaft retainer and bolts. Tighten to 106 inch lbs. (12 Nm).
     
    Timing chain and sprocket
     
    Valve lifters
     
    Valve lifter guides over the flats on the lifters. Make sure the rollers of the lifters are properly aligned with the cam lobes.
     
    Valve lifter guide retainer. Tighten the bolts to 18 ft. lbs. (25 Nm).
     
    Rocker arms and pushrods
     
    Intake manifold
     
    A/C condenser
     
    Grille
     

  6.  
  7. Recharge the A/C system.
  8.  

 
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