Cummins 4BT – Operation and Description – Front Gear Housing and Gear Train

The gear train consists of the crankshaft gear (1), lubri­cating oil pump gear (2), idler gear (3), the camshaft gear
(4), the fuel injection pump gear (5) and the accessory drive gear (6), if used.

The gear housing provides a support for the fuel injection pump, the timing pin and the accessory drive gear, if used.