LINK AS-TRACK 1171018 - Caterpillar

The valve clearance must be examined when the engine is still cold.
Remove the injection pipes, cylinder head cover, overflow pipes, and injectors.
Illustration 1 g03282877
Remove the plug (1) to gain access for the mark line on the flywheel.
Illustration 2 g02900945
Align the 1TC mark line on the flywheel and projection on the housing.
Make sure that the number one piston comes to the compression stroke or overlap top dead center.
Illustration 3 g03282936
(1) Adjusting Screw
(2) Lock Nut
(3) Feeler Gauge
Examine the subsequent valve clearance at the mark 1TC with a feeler gauge.
Turn the flywheel until the number one intake and exhaust valves are partially open and measure as shown in the table.
Table 1
Adjustable Cylinder Location of Piston Intake Exhaust
When number one piston is at compression top dead center. 1 X X
2 X
3 X
4
When number one piston is at overlap position. 1
2 X
3 X
4 X X
If the clearance is out of the factory specifications, adjust with the adjusting screw.
Table 2
C3.8 Engines Only
Valve clearance Factory specification 0.23 to 0.27 mm 0.0091 to 0.010 inch
Tighten the lock nut of the adjusting screw.