Rocker Arm Assembly: Service and Repair
REMOVAL1. Remove cylinder head cover.
2. Identify the rocker arm shaft assemblies before removal.
3. Loosen the attaching fasteners. Remove rocker arm shaft assemblies from cylinder head.
Fig. 48
4. Identify the rocker arms spacers and retainers for reassembly. Disassemble the rocker arm assemblies by removing the attaching bolts from the shaft (Fig. 48).
5. Slide the rocker arms and spacers off the shaft. Keep the spacers and rocker arms in the same location for reassembly.
Fig. 49
NOTE: Inspect the rocker arm for scoring, wear on the roller or damage to the rocker arm (Fig. 49) Replace if necessary. Check the location where the rocker arms mount to the shafts for wear or damage. Replace if damaged or worn. The rocker arm shaft is hollow and is used as a lubrication oil duct. Check oil holes for clogging with small wire, clean as required. Lubricate the rocker arms and spacers. Install onto shafts in their original position (Fig. 48).
INSTALLATION
CAUTION: Set crankshaft to 3 notches before TDC before installing rocker arm shafts. Refer to Timing Belt and Camshaft Oil Seal for procedure.
1. Install rocker arm/hydraulic lash adjuster assembly making sure that adjusters are at least partially full of oil. This is indicated by little or no plunger travel when the lash adjuster is depressed. If there is excessive plunger travel. Place the rocker arm assembly into clean engine oil and pump the plunger until the lash adjuster travel is taken up. If travel is not reduced, replace the assembly. Hydraulic lash adjuster and rocker arm are serviced as an assembly.
Fig. 50
2. Install rocker arm and shaft assemblies with NOTCH in the rocker arm shafts pointing up and toward the timing belt side of the engine (Fig. 50). Install the retainers in their original positions on the exhaust and intake shafts (Fig. 48).
CAUTION: When installing the intake rocker arm shaft assembly be sure that the plastic spacers do not interfere with the spark plug tubes. If the spacers do interfere rotate until they are at the proper angle. To avoid damaging the spark plug tubes, do not attempt rotating the spacers by forcing down the shaft assembly.
Fig. 51
3. Tighten bolts to 28 Nm (250 in. lbs.) in sequence shown in (Fig. 51).
4. Install cylinder head cover.
HYDRAULIC LASH ADJUSTER NOISE
A tappet-like noise may be produced from several items. Refer to Lash Adjuster (Tappet) Noise Diagnosis. Hydraulic Lash Adjuster Noise Diagnosis Lash adjusters are replaced with the rocker arm as an assembly.