Rocker arms and pushrods — removal, inspection and installation
Removal
1. Remove the valve cover (s) from the cylinder head(s) (see Valve covers — removal and installation).
2. Beginning at the front of one cylinder head, loosen and remove the rocker arms.
3. Keep track of the component positions, since they must be returned to the same locations. Store each set of components separately in a marked container to ensure that they’re reinstalled in their original locations.
4. Remove the pushrods and store them separately to make sure they don’t get mixed up during installation (see illustration).
5.4 A perforated cardboard box can be used to store the pushrods to ensure that they’re installed in their original positions — note the label indicating the front of the engine
Inspection
5. Check each rocker arm for wear, cracks and other damage, especially where the pushrods and valve stems contact the rocker arm (see illustration).
5.5 Rocker arm wear points
A Pushrod sockets
B Pivot bearing
C Valve stem contact point
6. Check the roller bearings in the rocker arms for free rotation. Make sure the hole at the pushrod end of each rocker arm is open.
7. Inspect the pushrods for cracks and excessive wear at the ends. Roll each push-rod across a piece of plate glass to see if it’s bent (if it wobbles, it’s bent).
8. Lubricate the lower end of each pushrod with clean engine oil or engine assembly lube and install them in their original locations. Make sure each pushrod seats completely in the lifter socket.
9. Apply engine assembly lube to the ends of the valve stems and to the upper ends of the pushrods to prevent damage to the mating surfaces on initial start-up. Also apply clean engine oil to the pivot shaft and bearing of each rocker arm and install the rocker arms loosely in their original locations. DO NOT tighten the bolts at this time!
10. Rotate the crankshaft until the number one piston is at TDC on the compression stroke (see Top Dead Center (TDC) for number one piston — locating). Both pushrods for the number one cylinder should be in the lowered position. When the number one piston is at TDC, tighten the intake valve rocker arms for the Number 1, 3 and 2 cylinders and the exhaust rocker arms for the Number 1, 5 and 6 cylinders. Tighten each of the specified rocker arm bolts to the torque listed in this Chapter’s Specifications.
11. Rotate the crankshaft 360 degrees. Tighten the intake valve rocker arms for the Number 5, 4 and 6 cylinders and the exhaust rocker arm for the Number 3, 2 and 4 cylinders. Tighten each of the rocker arm bolts to the torque listed in this Chapter’s Specifications.
12. Refer to Section Valve covers — removal and installation and install the valve covers. Start the engine, listen for unusual valve train noses and check for oil leaks at the valve cover gaskets.