SUPPORT AS 1192378 - Caterpillar

Valve Lash
Valve lash is measured between the rocker arm and the bridge for the valves. All of the valve lash measurements and valve lash adjustments must be made with the engine stopped. Also, the valves must be fully closed.Valve Lash Check
A valve lash adjustment is not necessary if the measurement of the valve lash is in the acceptable range. The acceptable range is given in Table 1.
Table 1
Valve Lash Check(1)
Valves Acceptable Range
Inlet 0.52 to 0.68 mm (0.020 to 0.027 inch)
Exhaust 0.92 to 1.08 mm (0.036 to 0.042 inch)
(1) Only perform the valve lash check while the engine is stopped.Use the procedure that follows in order to check valve lash:
Rotate the No. 1 piston to the top center position. Refer to Testing And Adjusting, "Finding the Top Center Position for the No. 1 Piston". With the No. 1 piston at the top center position of the compression stroke, check the valves. Refer to Crankshaft Position for Fuel Injector Adjustment and Valve Lash Setting.
Adjust the valve bridges. Refer to "Bridge Adjustment".
Insert the 6V-3075 Dial Indicator from the timing group into the 4C-6593 Adjustment Tool. Tighten the retaining screw finger tight. Note: Make sure that the 6V-3075 Dial Indicator is used with the short contact point.
Use the threaded hole that is nearest to the end of the rocker arm that will be adjusted in order to install the adjustment tool on the rocker base. Position the dial indicator stem over the flat area on the end of the rocker arm. Tighten the knob. Rotate the dial indicator so that the dial indicator can be easily read. Make sure that the adjustment tool is rigid and that the dial indicator stem moves freely.
Lift up firmly on the end of the rocker arm that has the adjustment screw and set the dial indicator to zero.
Lift up firmly on the valve end of the rocker arm and read the dial indicator.
Try to move the rocker arm while you are lifting up on the rocker arm. The dial indicator reading will vary. Read the dial indicator when the rocker arm is positioned in the groove of normal operation. Refer to Table 1 for the specifications regarding valve lash. If the dial indicator reading is within specifications move to the next valve.
If the dial indicator reading is not within specifications reset the valve lash. After the adjustment is complete proceed to the next valve. Refer to "Valve Lash Adjustment".
After completing all of the valve lash checks and the valve lash adjustments for this crankshaft position, remove the timing pin from the crankshaft. Rotate the crankshaft to the next position. Install the timing pin in the crankshaft. Repeat Steps 2 through 8.
Remove the timing pin from the crankshaft when all valve lash adjustments have been completed. Valve Lash Adjustment
The procedures for engine valve lash should be performed according to the information in the Service Manual.Operation of Caterpillar engines with improper valve adjustments will reduce engine efficiency. This reduced efficiency could result in excessive