24. SERVICE PROCEDURE 4. Place the STC tappet adjusting tool, Part No.3823348, on the upper surface of the STC injector top-cap. Rotate the tool around the tappet until the tool’s locating pin is inserted into one of the four holes in the top of the tappet. 5. Apply thumb pressure to the tool handle to hold the tappet in the maximum upward position. NOTE: Apply only enough force to the tool to hold the tappet in the maximum upward position. Excess force will cause the tool to break. 6. An overtightened setting on the injector adjusting screw will produce increased stress on the injector train and the camshaft injector lobe which can result in engine damage.
Use torque wrench, Part No.3376592, to tighten the adjusting screw while holding the tappet in the maximum upward position. Torque Value: 0.6 to 0.7 N•m [5 to 6 in-lb] 7. Hold the adjusting screw in this position. The adjusting screw must not turn when the locknut is tightened. Torque Value: Without Torque Wrench Adapter: 61 N•m [45 ft-lb] With Torque Wrench Adapter (1): 47 N•m [35 if-lb] 8. The tappet tool must be removed before rotating the crankshaft to prevent damage to the tappet. Remove the tappet adjusting tool. Check to make sure the injector push rod can be rotated by hand. If it can’t, the setting is too tight. PC450-ENG 3-69