Valve Clearance: Adjustments

Fig. 6 Adjusting Valve Lash:

After the engine has been thoroughly warmed up the valves may be adjusted, Fig. 6, with the engine shut off as follows: With engine in position to fire No. 1 cylinder the following valves may be adjusted: exhaust 1-2-3, intake 1-5-6. Then crank the engine one more complete revolution which will bring No. 4 cylinder to the firing position at which time the following valves may be adjusted: exhaust 4-5-6, intake 2-3-4.
The following procedure, performed with the engine running, should be done only in case readjustment is required.
1. After engine has been warmed up to operating temperature, remove valve cover and install a new valve cover gasket.
2. With engine running at idle speed, back off valve rocker arm nut until rocker arm starts to clatter.
3. Turn rocker arm nut down slowly until the clatter just stops. This is the zero lash position.
4. Turn nut down 1/4 additional turn and pause 10 seconds until engine runs smoothly. Repeat additional 1/4 turns, pausing 10 seconds each time, until nut has been turned down the number of turns listed in the Valve Lash Specifications Chart from the zero lash position. This preload adjustment must be done slowly to allow the lifter to adjust itself to prevent the possibility of interference between the intake valve head and top of piston, which might result in internal damage and/or bent push rods. Noisy lifters should be replaced.