ENGINE AR-PRIMARY 4815182 - Caterpillar

Illustration 1 g02059775
Location of the unit injector rocker arms on the right side of the engine (1) Unit injectors rocker arm
Illustration 2 g02148807
Location of the unit injector rocker arms on the left side of the engine (1) Unit injectors rocker armTo adjust the unit injector valve lash on cylinders 4, 5, 6, 9, 11, and 12 use the following procedure:
Remove the valve mechanism covers.
Put the No. 1 piston at the top center position on the compression stroke. Refer to Testing and Adjusting, "Finding Top Center Position for No. 1 Piston".
Illustration 3 g02148816
(2) Adjustment screw (3) Locknut (4) Unit injector
Turn the adjustment screw (2) counterclockwise until the screw does not contact the fuel injector.
Turn unit injector adjustment screw (2) clockwise until contact with unit injector (4) is made. Refer to Illustration 3.
Turn unit injector adjustment screw (2) clockwise for an additional 180 degrees.
Hold the adjustment screw in this position and tighten locknut (3) to a torque of 100 10 N m (74 7 lb ft).
To adjust the unit injector valve lash on cylinders 1, 2, 3, 7, 8, and 10 remove the timing bolt. Turn the flywheel by 360 degrees in the direction of engine rotation. The direction of engine rotation is counterclockwise, as the engine is viewed from the flywheel end. Rotating the engine will put the number 1 piston at the top center position on the exhaust stroke.
Repeat Steps 4 through 6.
Remove the timing bolt from the flywheel after all the unit injector adjustments have been made.
Install the valve mechanism covers.