Rocker Arms

CAUTION: 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.

REMOVAL
1. Remove cylinder head covers.





Fig.

2. Identify the rocker arm assembly and rocker arms before disassembly (Fig. 80).
3. Remove rocker arm assembly bolts.
4. Remove rocker arm assembly.

NOTE: To prevent air ingestion into lash adjusters, avoid turning rocker arm assembly upside down.

CAUTION: Do not allow rocker arm assembly to rest on lash adjusters, as damage may occur to lash adjusters and/or plastic retainers.

DISASSEMBLY





Fig.

1. Remove dowel pin using a 4 mm screw, nut, spacer, and washer installed into the pin (Fig. 81). Tighten the screw into the pin, then loosen the nut on the screw. This will pull the dowel out of the shaft support. Do not reuse dowel pins. Remove the rocker arms and pedestals in order.
2. Check the rocker arm mounting portion of the shafts for wear or damage. Replace if damaged or heavily worn.
3. Check shaft oil holes for clogging with small wire, clean as required.

ASSEMBLY

CAUTION: New dowel pins must be installed during assembly.

1. Install the rocker arms, and pedestals onto the shaft.

NOTE: The notches on the rocker shafts face up (Fig. 80). Notches on the right cylinder bank face towards rear of engine. Notches on left cylinder bank face toward front of engine.





Fig. 82

2. Install dowel pins (Fig. 82). Dowel pins pass through the pedestal into the exhaust rocker shafts. Dowel pins should be pressed in until they bottom out against the rocker shaft in the pedestal.

CAUTION: Inspect all lash adjuster plastic retaining caps for proper retention before installation.

INSTALLATION

NOTE: Rocker arm and shaft assembly can be installed either prior to or after (preferred) cylinder head installation.





Fig. 83

1. Rotate camshafts to the position shown in (Fig. 83). 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.
2. 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.





Fig. 84

3. Tighten rocker arm/shaft assembly bolts in sequence to 31 Nm (275 in. lbs.) (Fig. 84).