C3.3B Tier 4 Interim and EU Stage 3A Engines for Caterpillar Built Machines – Engine Valve Lash – Inspect/Adjust

Valve Lash Check

An adjustment is not necessary if the measurement of the valve lash is in the acceptable range. Valve lash must be checked with the engine stopped. The measurements are listed in Table 1.

Table 1
Valve Lash    
Valve Lash Setting     Inlet Valves     Exhaust Valves    
0.13 mm (0.00512 inch) to
0.17 mm (0.00669 inch)

0.13 mm (0.00512 inch) to
0.17 mm (0.00669 inch)    
Firing Order     1-3-4-2 (1)    
( 1 ) No. 1 cylinder is at the front of the engine

Valve Lash Adjustment

Table 2
Location of
Valve Arrangement    
Inlet Exhaust    
Piston No.1
Top Center    
1     X     X    
2 X    
3     X    
Piston No. 1
Is At
2     X    
3 X        
4 X     X    

Adjust the valve lash while the engine is stopped. Use the following procedure in order to adjust the valves:

    Illustration 1g03332004

    Location of timing window

    Illustration 2g02918462

    View of correctly aligned top center mark

  1. Align the top center mark of the flywheel and the convex of the timing window that is on the flywheel housing. This brings the No. 1 cylinder to the top center position.

    Illustration 3g02918557

    (1) Adjusting screw

    (2) Locknut

  1. Loosen locknut (2) of adjusting screw (1) , and insert feeler gauge between the rocker arm and the head of the valve bridge arm. Set the adjusting screw to the specified value, and tighten the locknut.

    Note: After adjustment, tighten the locknut securely.

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