STEP GP 3890241 - Caterpillar

To prevent possible injury, do not use the starter to turn the flywheel. Hot engine components can cause burns. Allow additional time for the engine to cool before measuring valve clearance.
This engine uses high voltage to control the fuel injectors.Disconnect electronic fuel injector enable circuit connector to prevent personal injury.Do not come in contact with the fuel injector terminals while the engine is running.
Note: Valve lash is measured between the rocker arm and the valve bridge. All measurements and adjustments must be made with the engine stopped and the valves fully closed.Valve Lash Check
An adjustment is NOT NECESSARY if the measurement of the valve lash is in the acceptable range. Check the valve lash while the engine is stopped. The range is specified in Table 1.
Table 1
Valve Lash
Valves Acceptable Range for Valve Lash
Inlet 0.38 0.08 mm (0.015 0.003 inch)
Exhaust 0.76 .08 mm (0.030 0.003 inch) If the measurement is not within this range adjustment is necessary. Refer to Testing And Adjusting, "Valve Lash Adjustment".Valve Lash Adjustment
Illustration 1 g00561261
(A) Inlet valves
(B) Exhaust valves
(C) Left side of the engine
(D) Cylinder number
(E) Front of the engine
(F) Right side of the engine
(G) Flywheel end of the engine
Illustration 2 g00506544
(1) Valve adjustment locknut
(2) Exhaust adjustment screw
(3) Valve adjustment locknut
(4) Inlet adjustment screw
(5) Feeler gauge
Table 2
Valve Lash
Valves Gauge Dimension
Inlet 0.38 mm (0.015 inch)
Exhaust 0.76 mm (0.030 inch) Adjust the valve lash while the engine is stopped. Use the following procedure in order to adjust the valves:
Put the No. 1 piston at the top center position. Note: If the engine is equipped with an engine compression brake, loosen the adjusting screw for the lash on the slave piston for the compression brake prior to adjusting the engine valve lash. Refer to the Testing and Adjusting, "Slave Piston Lash - Adjust" topic in order to adjust the slave piston lash.Note: See Testing and Adjusting, "Finding Top Center Position for the No. 1 Piston" for further details.
With No. 1 piston at the top center position of the compression stroke, an adjustment can be made to the valves. Before any adjustments are made, lightly tap each rocker arm at the top of the adjustment screw. Use a soft mallet to ensure that the lifter roller seats against the camshaft's base circle.
Make an adjustment to the valve lash on the inlet valves for cylinders 1, 2, and 4.
Loosen valve adjustment locknut (3).
Place the appropriate