Valves Adjustment

The procedures given in this section for valve lash adjustment are to be performed at the initial 38,000 km [24,000 mi] adjustment. Subsequent adjustments are to be performed at 77,000 km [48,000 mi] intervals.

With a 15 mm wrench, remove the valve cover.

Cummins diesel engine valves adjustment

1/2 Inch Drive, 3824591 Engine Barring Gear

 Locate Top Dead Center (TDC) for Cylinder Number 1 by barring engine slowly while pressing on the engine timing pin.  The barring gear inserts into the flywheel housing and engages the flywheel ring gear. The engine can then be rotated by hand using a 1/2 inch ratchet or breaker bar.

Cummins diesel engine valves adjustment

When the pin engages the hole in the camshaft gear, Cylinder Number 1 is at TDC on the compression stroke.

CAUTION: To prevent damage to the engine or pin, be sure to disengage the pin after locating TDC

Cummins diesel engine valves adjustment feeler guage

Feeler Gauge  Intake Clearance: 0.254 mm [0.010 IN]  Exhaust Clearance: 0.508 mm [0.020 IN]  Check/set valves with engine cold - below 60° C [140° F].

NOTE: The clearance is correct when some resistance is “felt” when the feeler gauge is slipped between the valve stem and the rocker lever.

Cummins diesel engine valve adjustment 6cyl

 

 Six-Cylinder Engine Adjustment  

14 mm wrench, Flatblade Screwdriver  

Locate Top Dead Center (TDC) for Cylinder Number 1  Check/adjust the valves as indicated in the illustration (I = Intake, E = Exhaust).  Tighten the lock nut and measure the valve lash again.  Torque Value: 24 N•m [18 ft-lb]   Mark the pulley/vibration damper and rotate the crank-shaft 360 degrees.

   CAUTION: To prevent engine or pin damage, be sure timing pin is disengaged.

Cummins diesel engine valves adjustment

Adjust the valves as indicated in the illustration.  Tighten the lock nut and measure the valve lash again.  Torque Value: 24 N•m [18 ft-lb]  

With a 15 mm wrench, install the valve covers and tighten capscrews.  Torque Value:  24 N•m [18 ft-lb]