Valve lash is measured between the rocker arm and the valve. All lash measurements and adjustments must be made with the engine stopped, and with the valves FULLY CLOSED.
Valve Lash Check
When the valve lash is checked, adjustment is NOT NECESSARY if the measurement is in the range given in the chart VALVE LASH CHECK: ENGINE STOPPED. If the measurement is outside this range, adjustment is necessary. See the chart for VALVE LASH SETTING: ENGINE STOPPED, and make the setting to the nominal (desired) specifications in this chart. Refer to Operation And Maintenance Manual for service interval for valve lash adjustment.
NOTE: For valve lash specifications and measurement procedure refer to Fuel System; Crankshaft Positions For Valve Lash Setting, located in this manual.
3100 HEUI Diesel Truck Engine Cylinder And Valve Location