Gear Group (Front) – Remove and Install


Removal Procedure

Tool Part
A - 21825576  Crankshaft Turning Tool
B - 27610212  Camshaft Timing Pin
C - 27610286  Crankshaft Timing Pin

Remove the front cover. Remove the valve mechanism cover. Either Tooling (A) can be used. Use the Tooling that is most suitable. Care must be taken in order to ensure that the fuel injection pump timing is not lost during the removal of the front gear group. Carefully follow the procedure in order to remove the gear group.
Use Tooling (A) in order to rotate the crankshaft so that number one piston is at top dead center on the compression stroke.


Install Tooling (B) through the hole (X) in the camshaft gear (1) into the front housing. Use Tooling (B) in order to lock the camshaft in the correct position.


Remove the plug (4) from the cylinder block. Install Tooling (C) into the hole (Y) in the cylinder block. Use Tooling (C) in order to lock the crankshaft in the correct position. Do not use excessive force to install Tooling (C). Do not use Tooling (C) to hold the crankshaft during repairs.


Loosen the nuts (6) on all rocker arms (7). Unscrew the adjusters (5) on all rocker arms (7) until all valves are fully closed.
Failure to ensure that ALL adjusters are fully unscrewed can result in contact between the valves and pistons.
Apply sufficient pressure to the fuel injection pump gear (3) in a counterclockwise direction in order to remove the backlash. Lock the fuel injection pump in this position.


Mark the gears (1), (2) and (3) in order to show alignment. Refer to Illustration. Identification will ensure that the gears can be installed in the original alignment. Remove the fuel pump gear (3). Remove the camshaft gear (1). Remove the idler gear (2).

Installation Procedure

The fuel injection pump must remain locked until the procedure instructs you to unlock the fuel injection pump. Ensure that number one piston is at top dead center on the compression stroke.


If necessary, install Tooling (C) into the hole (Y) in the cylinder block. Use Tooling (C) in order to lock the crankshaft in the correct position.
Do not use excessive force to install Tooling (C). Do not use Tooling (C) to hold the crankshaft during repairs. Ensure that all of the components of the front gear group are clean and free from wear of damage. If necessary, replace any components that are worn or damaged.


Install the camshaft gear (1). Loosely install the setscrew (6) and the washer (5) for the camshaft gear


Install Tooling (B) through the hole (X) in the camshaft gear (1) into the front housing.



Alignment of timing marks

Install the idler gear (2). Ensure that the timing marks on the gears (1) and (2) are in alignment and that the mesh of the gears is correct. Check the end play of the idler gear.
Tighten the setscrew (6) for the camshaft gear to a torque of 95 N·m (70 lb ft). Check the end play of the camshaft gear.
Ensure that the fuel injection pump is locked in the correct position.
Install the fuel injection pump gear (3). Ensure that the timing marks on the gears (2) and (3) are in alignment. See Illustration. Ensure that the mesh of the gears is correct. Remove the Tooling (B) and (C). Install the plug (4) into hole (Y) in the cylinder block. Refer to Illustration.


Checking backlash

Ensure that the backlash for the gears (1), (2) and (3) is within specified values. Lubricate each gear with clean engine oil. Adjust the engine valve lash.