Removal & Installation
The rocker arm shafts are hollow and are used as lubrication oil passages. The rocker arm and shaft assembly on the RIGHT side of the engine has an oil passage hole from the cylinder head to the third rocker shaft support. The rocker arm shaft assembly on the LEFT side of the engine has an oil passage hole from the cylinder head to the second rocker shaft support.
- Remove cylinder head covers. Refer to procedure in this section.
- Identify the rocker arm assembly and rocker arms before disassembly
- Remove rocker arm assembly bolts.
Remove rocker arm assembly
NOTETo prevent air ingestion into lash adjusters, avoid turning rocker arm assembly upside down.
CAUTIONDo not allow rocker arm assembly to rest on lash adjusters, as damage may occur to lash adjusters and/or plastic retainers
Rocker arm and shaft assembly can be installed either prior to or after (preferred) cylinder head installation.
- Rotate camshafts to the neutral position. With the camshafts in these positions the lobes are in a neutral position (no load to the valve) This will allow the rocker arm shaft assembly to be tightened into position with little or no valve spring load on it.
- Install the rocker arm and shaft assembly making sure that the identification marks face toward the front of engine for left head and toward the rear of the engine for right head.
- Tighten rocker arm/shaft assembly bolts in sequence to 275 inch lbs. (31Nm)
- Before servicing the vehicle, refer to the Precautions section.
- Relieve the fuel system pressure.
Remove or disconnect the following:
NOTECover the lower intake manifold during service.
Negative battery cable
Inspect the rocker arms for wear or damage. Inspect the roller for scuffing or wear. Replace assembly as necessary.
WARNINGDo not remove the lash adjusters from the rocker arm assembly. The rocker arm and the adjuster are serviced as an assembly.
Identify the rocker arm assemblies and rocker arms and disassemble the shaft as follows:
- Thread a nut, washer and spacer onto a 4mm screw.
- Insert and tighten the 4mm screw into the dowel pin on the shaft.
- Loosen the nut on the screw. This will pull the dowel pin from the shaft support.
- Remove the rocker arms and pedestals, keeping them in order.
Check the oil holes for restrictions with a small wire and clean as required.
Assemble the rocker shaft as follows:
- Install the rocker arms and pedestals onto the shaft, keeping them in the original order.
- Press the dowel pins into the pedestals until they bottom out in the pedestals.
- Position the camshaft so that the timing mark on the right camshaft timing belt sprocket aligns with the timing mark on the rear timing belt cover and the timing mark on the left sprocket is 45 degrees from the mark on the rear timing belt cover. There will be no load on the shaft during installation. Install the rocker shafts so the identification marks are facing toward the front of the engine.
Install the oil feed bolt in the correct location on the rocker shaft retainer. Torque the bolts in proper sequence to 23 ft. lbs. (31 Nm).
Install or connect the following:
Valve covers and torque the bolts to 105 inch lbs. (12 Nm)