Montana, Silhouette, Venture 2000-2005

Rocker Arms

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Removal & Installation




NOTE
Valve train components which are to be reused must be installed in their original positions. If removed, be sure to tag or arrange all rocker arms and pushrods to assure proper installation.

  1. Before servicing the vehicle, refer to the Precautions Section.
  2.  
  3. Remove or disconnect the following:
    NOTE
    Place the valve train parts in order to ensure they are installed in the proper location. Intake pushrods are yellow and measure 5.68 inches (144.18mm). Exhaust pushrods are green and measure 6.0 inches (152.51mm). When removing the pushrods, make certain they do not fall into the lifter valley.



    Negative battery cable
     
    Rocker arm cover
     
    Rocker arm bolts
     
    Rocker arms
     



    Pushrods
     

  4.  

To install:

  1. Inspect and replace components if worn or damaged. Clean all old thread locking material from the pedestal bolts.
  2.  
  3. Coat the bearing surface of the rocker arms, pushrods and rocker arm bolts with a prelube (such as GM 1052365). Make certain to install the components in their original position.
  4.  
  5. Install or connect the following:

    Intake valve pushrods which are 5.68 inches (144.18mm) long
     
    Exhaust valve pushrods which are 6.0 inches (152.51mm) long
     
    Rocker arms. Torque the bolt to 14 ft. lbs. (19 Nm) plus 30 degrees
     
    Rocker arm cover. Torque the bolt to 89 inch lbs. (10 Nm).
     
    Negative battery cable
     

  6.  
  7. Start the engine and verify the vehicle is running properly.
  8.  

3.5L Engine
  1. Before servicing the vehicle, refer to the Precautions Section.
  2.  
  3. Partially drain the cooling system (left side only)
  4.  
  5. Remove or disconnect the following:
    CAUTION
    Rocker arm cover gasket and sealant must be carefully trimmed away from the lower intake manifold gasket. Failure to do so will damage the lower intake manifold gasket and cause a severe oil leak.


    CAUTION
    Keep components separated in order to reinstall in the same location.



    Negative battery cable
     
    Drive belt (Right)
     
    Generator (Right)
     
    Generator bracket (Right)
     
    Spark plug wires
     
    Vacuum hoses from the EVAP purge valve (Right)
     
    EVAP purge valve (Right)
     
    Ignition coil bracket and coils (Right)
     
    Thermostat bypass pipe (Left)
     
    PCV vacuum hose (Left)
     
    Rocker arm cover bolts and cover
     
    Trim the valve cover sealant away from the lower intake manifold gasket at the cylinder head to the lower intake manifold joints
     



    Rocker arm bolts
     
    Rocker arms
     



    Click image to see an enlarged view

    Fig. Lower intake manifold joint



    Click image to see an enlarged view

    Fig. Lower intake manifold torque sequence

  6.  

To install:

  1. Install or connect the following:
    NOTE
    Use an alternating criss-cross pattern when tightening the rocker cover bolts. Failure to do so may cause an oil leak due to improper seating of the gasket.



    Rocker arms
     
    Rocker arm bolts and tighten to 24 ft. lbs. (32 Nm)
     
    Apply sealant (GM P/N12378521 or equivalent) at the cylinder head to lower intake manifold joint (1)
     
    New gasket and rocker arm cover, tighten bolts to 89 inch lbs. (10 Nm)
     



    PCV vacuum line (Left)
     
    Thermostat bypass pipe (Left)
     
    Ignition coil bracket and coils (Right)
     
    EVAP purge valve (Right)
     
    Vacuum hose to EVAP purge valve (Right)
     
    Spark plug wires
     
    Generator bracket (Right)
     
    Generator (Right)
     
    Drive belt (Right)
     
    Negative battery cable
     
    Refill cooling system (Left)
     

  2.  
  3. Start and run the engine to check for leaks.
  4.  

3.9L Engine
  1. Before servicing the vehicle, refer to the Precautions Section.
  2.  
  3. Remove the valve covers. For additional information, please refer to the following section, -Valve Cover, Removal & Installation.-
  4.  
  5. Remove the rocker arm bolts.
  6.  
  7. Remove the rocker arms and pushrods.
    NOTE
    Keep all valvetrain components in order.


    NOTE
    The intake pushrods measure 5.81 in. (147.51 cm) and the exhaust pushrods measure 6.1 in. (154.87 cm).

  8.  

To install:

  1. Coat the ends of the pushrods with prelube.
  2.  
  3. Install the pushrods. Ensure that the pushrods seat properly in the lifter bore.
  4.  
  5. Coat the rocker arm friction surfaces with prelube.
  6.  
  7. Install the rocker arms and tighten the rocker arm bolts to 25 ft. lbs. (34 Nm).
  8.  
  9. Install the valve covers.
  10.