BOLT 7J8902 - Caterpillar

Engine: Commercial with Electronic Unit Injection
3500 Series Engine: Commercial
3500B Series
Illustration 1 g00284803
(1) Rocker arm shaft bolt (2) Rocker arm shaft
Illustration 2 g01030120
(3) Dimension for the lash settingIt is important to properly set the fuel injector timing to the correct height dimension. If this dimension is set improperly poor engine performance or damage to the valve train could result. Rocker arm shaft bolts have broken at low hours in the field on some 3500B Engines. There have been three to four failures of the rocker shaft bolt per year. The failures have occurred throughout a range of applications on 3500B Engines. The failures of the rocker arm bolt have been tied to the dimension for the injector. The lash setting for the fuel injector was improperly adjusted. This adjustment is critical. Ensure that the adjustment of the fuel injector is made properly:
Ensure that the injector tappet is clean.
Ensure that the calibration tool is clean.
Verify that the indicator on the calibration tool returns to zero after setting the injectors.Refer to your specific Operation and Maintenance Manual, "Maintenance Interval Schedule" for the proper service interval.Refer to your specific Testing and Adjusting, "Fuel Injector Adjustment" for the complete adjustment procedure.