REMOVAL & INSTALLATION 4-134 Engines
See Figure 1
- Remove the rocker arm cover attaching bolts and remove the rocker arm cover.
- Remove the nuts from the rocker arm shaft support studs.
- Remove the intake valve pushrods from the engine.
- Installation is the reverse of removal. Tighten the rocker arm retaining bolts to 30-36 ft. lb.
See Figure 2
- Remove the crankcase ventilator valve from the right side valve cover.
- Remove the four attaching bolts from the right and left side valve covers and remove both of the valve covers.
- Unscrew, but do not remove, the bolts that attach the rocker arm assemblies to the cylinder heads.
- Remove the rocker arm assemblies, with the bolts in place, from the cylinder heads. Mark each of the pushrods so that they can be installed in their original positions.
- Remove the pushrods.
- Installation is the reverse of removal. Tighten the bolts to 30 ft. lb., a little at a time.
- Remove the camshaft cover.
- Remove the rocker arm-to-stud nuts and lift off the rocker arms and balls.
- Install the rocker arm and ball on the stud.
- Install, but do not tighten, the rocker arm nut.
- When all removed arms are installed, adjust the valves, being very careful to precisely align the rocker arms while tightening the nut!
6-232, 8-350 and 1971-72 6-258 Engines
- Remove the valve cover by removing the valve cover attaching screws.
- Loosen evenly, but do not remove, the bolts that attach the rocker arm assembly to the cylinder head.
- Lift the whole rocker arm assembly off the head with the bolts in place.
- Identify each of the pushrods so that they can be replaced in their original positions. Remove the pushrods.
- Installation is the reverse of removal. Tighten the mounting bolts, working evenly, from the center outward. Tighten to 22 ft. lb.
8-304, 8-360, 8-401 and 1973 and later 6-258 Engines
See Figure 3
- Unscrew the rocker retaining nut from the stud and lift off the rocker arm and its pivot ball.
- To remove the stud from the block use a pliers and wrench.
- Label the pushrods to that they can be installed in their original positions and remove them from the block.
- When installing the rocker arm retaining studs, use caution not to cross thread them. They are designed to cause an interference fit. Lubricate the studs with high pressure grease before installing them in the head. Install the rocker arm assemblies in the reverse order of removal. Tighten the rocker arm retaining nuts to 23 ft. lb.
See Figure 4
- Remove the rocker arm cover to gain access to the rocker shafts by removing the wing nuts, flat washers and grommets holding the covers to the cylinder heads and lift the covers off together with the gaskets.
- Loosen the rocker arm hold-down bolts evenly to release the strain on the shaft and binding on the bolts.
- Remove the bolts and rocker arms. If the rocker arm shaft dowels stay with the cylinder head, remove them and install them in the supports.
When removing the rocker arms, while the engine is installed in the vehicle, loosen the radiator cap to relieve the pressure in the cooling system before loosening the bolts to prevent coolant seepage.
- If the rocker arm assembly is disassembled, mark the rockers themselves so that they can be reassembled onto the shaft in the same order from which they were removed.
- If the pushrods are removed, they should also be identified so that they can be reinstalled in the same position from which they were removed.
- Installation is the reverse of removal. Note that the rocker shaft bolts are also head bolts. Torque them in alternating sequence, from the ends to the middle. Bolt torque is 60-65 ft. lb.