Quest 1995-1996

Rocker Arms & Shafts

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Description



Specific to:

Mercury Villager 1993-2000

Nissan Quest 1993-2000

There are two rocker arm shafts on each cylinder head, with three rocker arms on each shaft. One shaft is for the intake valves, and the other is for the exhaust valves.

Inspection



Specific to:

Mercury Villager 1993-2000

Nissan Quest 1993-2000

If excess rocker arm wear is suspected, measure the rocker arm-to-rocker arm shaft clearance. For specifications, please refer to Engine Mechanical Specifications, Rocker Arm Shaft and Rocker Arm Specifications. Measure the outer diameter of the rocker arm shaft with a micrometer. Record the measurements, if they are within specifications. If the measurements are less than specifications, the shaft is worn and must be replaced.

Using an bore gauge or inside micrometer, measure the inner diameter of the rocker arm. Record the measurements, if they are within specifications. If the rocker arm inner diameter is greater than specifications, the rocker arm must be replaced.

To find the rocker arm-to-rocker arm shaft clearance, subtract the previously recorded rocker arm shaft diameter from the recorded inner diameter of the rocker arm.

Removal & Installation



Specific to:

Mercury Villager 1993-2000

Nissan Quest 1993-2000

  1. Remove the rocker arm cover.
  2.  
  3. On 1999-00 3.3L engines, if the right side rocker arms and shafts are being removed:
    1. Disconnect the right side fuel injector electrical connectors.
    2.  
    3. Disconnect the knock sensor and EGR solenoid electrical connectors.
    4.  
    5. Position the wiring harness out of the way.
      WARNING
      Loosening the rocker arm shaft bolts in one step may distort or break the rocker arm shaft.

    6.  

  4.  
  5. Loosen the rocker arm shaft bolts in two or three steps. Mark the location of the rocker arms to ease installation.
    NOTE
    Do not move the rocker arm shaft support with the rocker arm shaft bolts removed. The valve lifters are located in the support, and should remain in their original positions. For valve lifter servicing, please refer to Rocker Arm Shaft Supports and Lifters.

  6.  
  7. Remove the rocker shafts with rocker arms, as an assembly.
  8.  
  9. Slide the rocker arms off of the shaft.
    NOTE
    When separating the rocker arms from the rocker arm shafts, be sure to keep the parts in order for reinstallation, if any of the parts are to be reused.

  10.  

To install:

  1. Clean the parts with solvent. Check the rocker arms and the shafts for damage. Any worn parts should be replaced.
    WARNING
    When installing the rocker arms on the shafts, be certain that they are installed in their original positions.

  2.  
  3. Lubricate the rocker arms and shafts with new motor oil. Slide the rocker arms onto the shafts.
  4.  
  5. Rotate the engine so that the camshaft is turned to a position where the valves for the shaft being installed will be closed.
    WARNING
    Tightening the rocker arm shaft bolts while the camshaft is positioned to open the valves may result in damaged valve components.

  6.  
  7. Rotate the engine until cylinder No. 1 is at TDC of the compression stroke.
  8.  
  9. Install the rocker arm shafts for No. 2, No. 4, and No. 6 cylinders. Tighten the bolts gradually, in three steps, to 13-16 ft. lbs. (18-22 Nm).
  10.  
  11. Rotate the engine 360°, so that cylinder No. 4 is at TDC of the compression stroke.
  12.  
  13. Install the rocker arm shafts for No. 1, No. 3, and No. 5 cylinders. Tighten the bolts gradually, in three steps, to 13-16 ft. lbs. (18-22 Nm).
  14.  
  15. When installing the right side rocker arms and shafts on 1999-00 3.3L engines, connect the EGR solenoid, knock sensor, and fuel injector electrical connectors.
  16.  
  17. Install the rocker arm cover with a new gasket.
  18.  

 
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