Rocker Arm Assembly: Service and Repair
Valve Rocker Arm, Shaft, and Push Rod ReplacementRemoval Procedure
1. Disconnect the battery negative cables from the batteries.
2. Remove the engine cover from the vehicle.
3. Remove the valve rocker arm cover(s).
4. Remove the bolts for the valve rocker arm shaft. There are two shafts for each cylinder head.
Notice: All valve train components must be reassembled in the exact order and position from which they were removed.
5. Remove the valve rocker arm shaft with the valve rocker arms.
Important: The push rods have different degrees 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.
6. Remove the push rods from the engine block.
7. Use a pair of pliers to break off the end of the nylon valve rocker arm retainers from the valve rocker arm shaft.
8. Remove the valve rocker arm retainers with a pair of pliers.
9. Slide the valve rocker arms from the rocker arm shaft.
10. Clean the parts in solvent.
^ Wear protective safety glasses and gloves.
^ Blow-dry the parts with compressed air.
11. Inspect the valve rocker arms and shafts at the mating surfaces, in order to ensure that they are smooth and without scoring damage.
12. Inspect the valve rocker arm areas, which contact the valve stems and the sockets, which contact the valve pushrods. These areas should be smooth and without damage or wear.
13. Determine if the valve pushrods are bent by rolling the pushrod on a flat surface.
14. Replace the pushrod if the pushrod is bent.
15. Inspect the ends of the valve pushrods for scoring or roughness.
16. Make sure the Oil passages in the valve pushrods are clear.
17. Replace any damaged parts.
Installation Procedure
Notice: All valve train components must be reassembled in the exact order and position from which they were removed.
Notice: Install the valve pushrods with the copper-colored, painted, or marked end up in order to avoid damage or premature wear.
Important: Lubricate the valve rocker arms, the shafts, and the push rod ends with clean engine Oil before Installing.
1. Install the push rod, with the painted or marked end up to the engine block.
2. Install the valve rocker arms to the valve rocker arm shaft. One type of valve rocker arm is used at all locations.
3. Install the valve rocker arm retainers to valve rocker arm shaft.
3.1. Center the valve rocker arm on the corresponding holes in the valve rocker arm shaft.
3.2. Use a drift of at least 13 mm (1/2 inch) in diameter to Install new retainers to the valve rocker arm shaft.
Notice: Improper Installation of the valve rocker arm shaft bolts may cause valve rocker arm shaft breakage and piston to valve contact.
Important: You must rotate the engine in the proper position in order to prevent damage to the valves or the pistons.
4. Using the following procedure rotate the engine in order to properly Install the valve rocker arm shafts. This will position the engine so that no valves are close to the piston crown.
4.1. Rotate the engine until the mark on the crankshaft balancer is at the 2 o'clock position.
4.2. Rotate the crankshaft counter clockwise 88 mm (31/2 inch), aligning the crankshaft balancer mark with the first lower water pump bolt, about 12:30.
5. Install the valve rocker arm shaft assembly to the cylinder head. Ensure the push rods are located properly in the valve rocker arms.
Notice: Refer to Fastener Notice in Service Precautions.
6. Install the valve rocker arm shaft bolts to the cylinder head.
^ Tighten the bolts to 55 Nm (40 ft. lbs.).
7. Install the valve rocker arm cover(s).
8. Install the engine cover.
9. Connect the battery negative cables to the batteries.