Rocker Arm Assembly: Service and Repair
REMOVAL PROCEDUREIMPORTANT: Rotate the engine until the mark on the crankshaft balancer is at the 2 o'clock position.
Rotate the crankshaft counter clock wise 88 mm (3 1/2 inch), aligning the crankshaft balancer mark with the first lower water pump bolt, about 12:30.
This will position the engine so that no valves are close to the piston crown.
1. Disconnect both the battery negative cables from the batteries. Refer to Battery Cable in Powertrain Management.
2. Remove the valve rocker arm cover from the cylinder head. Refer to Valve Rocker Arm Cover Replacement.
NOTICE: All valve train components must be reassembled in the exact order and position from which they were removed.
3. Remove the valve rocker arm shaft bolts from the cylinder head.
4. Remove the valve rocker arm shaft with the valve rocker arm.
IMPORTANT: The push rods must be installed in the original direction as disassembly. This is because the push rods have different° of hardness at each end. A paint stripe identifies the upper end of the push rod. If the paint stripe is not visible, mark the push rod on the upper end as the push rods are removed.
5. Remove the push rods from the engine block.
6. Remove the valve rocker arms from the cylinder head.
7. Insert a screwdriver into the valve rocker arm shaft bore and break off the end of the nylon valve rocker arm retainers.
8. Remove the valve rocker arm retainers with a pair of pliers.
9. Slide the valve rocker arms from the rocker arm shaft.
10. Inspect each of the valve train components. Refer to Valve Rocker Arm and Shaft Clean and Inspect.
INSTALLATION PROCEDURE
NOTICE: All valve train components must be reassembled in the exact order and position from which they were removed.
IMPORTANT: Lubricate the valve rocker arms with clean engine oil before installing.
1. Install the valve rocker arms to the valve rocker arm shaft (one type of valve rocker arm is used at all locations) to the cylinder head.
2. Install the valve rocker arm retainers to the cylinder head.
3. Center the valve rocker arm on the corresponding holes in the valve rocker arm shaft.
4. Use a drift of at least 13 mm (1/2 inch) in diameter to install new retainers to the valve springs.
NOTICE: Install the valve pushrods with the copper-colored, painted, or marked end up in order to avoid damage or premature wear.
5. Install the push rod, with the painted or marked end up to the engine block.
NOTICE: Improper installation of the valve rocker arm shaft bolts may cause valve rocker arm shaft breakage and piston to valve contact.
6. Install the valve rocker arm shaft assembly to the cylinder head.
NOTICE: Refer to Fastener Notice in Service Precautions.
7. Install the valve rocker arm shaft bolts to the cylinder head.
^ Tighten the bolts to 55 Nm (40 ft. lbs.).
8. Install the valve rocker arm cover to the cylinder head. Refer to Valve Rocker Arm Cover Replacement.
9. Connect both the battery negative cables to the batteries. Refer to Battery Cable in Powertrain Management.