The operation of the injection pump is performed by gears inside the front cover (see Figure 2-32). The injection pump drive gear mounts on the front of the camshaft and rotates at one-half the rotating speed of the crankshaft. The front cover-mounted injection pump supports the driven gear, which mounts to the injection pump drive shaft with three bolts. Alignment marks on the front cover and the injection pump provide a static timing of fuel injection.
A roller bearing inside the injection pump is used for injection pump drive shaft support and is lubricated by engine oil splashed inside the front cover. A spring-loaded button on the front of the injection pump drive shaft rests against a metal finger on the back of the water pump plate inside the front cover.
As part of installing a new front cover, the static timing mark must be made for alignment with the injection pump.
The steps are as follows:
1. With the injection pump removed, rotate the engine to the TDC position for the #1 piston so that the slot in the injection pump driven gear is in the 6 o’clock position (see Figure 2-33, view A).
2. Install the special timing fixture (J 33042) to the injection pump driven gear, using the bolt provided with the tool.
3. Retain the special timing fixture against the front cover, using the top injection pump mounting stud and nut (finger tighten).
4. Rotate the special tool toward the engine left cylinder head with 48 N-m (35 Ib-ft) torque, and strike the scribe of the tool with a mallet (see Figure 2-33, view B).
5. Complete the front cover installation steps.
