C6.6 Engines for Caterpillar Built Machines Gear Group (Front) - Remove and Install Caterpillar

Removal Procedure

Start By:

1. Remove the front cover. Refer to Disassembly and Assembly, "Front Cover - Remove and Install".
2. Remove the valve mechanism cover. Refer to Disassembly and Assembly, "Valve Mechanism Cover - Remove and Install".

Note: 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.

1. Use Tooling (A) in order to rotate the crankshaft so that number one piston is at top dead center on the compression stroke. Refer to System Operation, Testing and Adjusting, "Finding Top Center Position for No.1 Piston".

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Illustration 1	g01335379
Typical example

2. Install Tooling (B) through hole (X) in camshaft gear (1) into the front housing. Use Tooling (B) in order to lock the camshaft in the correct position. Refer to System Operation, Testing and Adjusting, "Finding Top Center Position for No.1 Piston".

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Illustration 2	g01335380

3. Remove plug (4) from the cylinder block. Install Tooling (C) into hole (Y) in the cylinder block. Use Tooling (C) in order to lock the crankshaft in the correct position. Refer to System Operation, Testing and Adjusting, "Finding Top Center Position for No.1 Piston".

   Note: Do not use excessive force to install Tooling (C) . Do not use Tooling (C) to hold the crankshaft during repairs.

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Illustration 3	g01337898

4. Loosen nuts (6) on all rocker arms (7) . Unscrew adjusters (5) on all rocker arms (7) until all valves are fully closed.

   Note: Failure to ensure that ALL adjusters are fully unscrewed can result in contact between the valves and pistons.

5. Apply sufficient pressure to fuel injection pump gear (3) in a counterclockwise direction in order to remove the backlash. Lock the fuel injection pump in this position. Refer to Disassembly and Assembly, "Fuel Pump Gear - Remove" for the correct procedure.

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Illustration 4	g01335384
Typical example

6. Mark gears (1) , (2) and (3) in order to show alignment. Refer to Illustration 4.

   Note: Identification will ensure that the gears can be installed in the original alignment.

7. Remove fuel pump gear (3) . Refer to Disassembly and Assembly, "Fuel Pump Gear - Remove and Install" for the correct procedure.

8. Remove camshaft gear (1) . Refer to Disassembly and Assembly, "Camshaft Gear - Remove and Install".

9. Remove idler gear (2) . Refer to Disassembly and Assembly, "Idler Gear - Remove and Install".

Installation Procedure

Note: The fuel injection pump must remain locked until the procedure instructs you to unlock the fuel injection pump.

1. Ensure that number one piston is at top dead center on the compression stroke. Refer to System Operation, Testing and Adjusting, "Finding Top Center for No. 1 Piston".

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Illustration 5	g01335380

2. If necessary, install Tooling (C) into hole (Y) in the cylinder block. Use Tooling (C) in order to lock the crankshaft in the correct position. Refer to System Operation, Testing and Adjusting, "Finding Top Center Position for No.1 Piston".

   Note: Do not use excessive force to install Tooling (C) . Do not use Tooling (C) to hold the crankshaft during repairs.

3. 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.

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Illustration 6	g01337904

4. Install camshaft gear (1) . Loosely install bolt (6) and washer (5) for the camshaft gear. Refer to Disassembly and Assembly, "Camshaft Gear - Remove and Install" for more information.

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Illustration 7	g01335379
Typical example

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

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Illustration 8	g01337905
Typical example

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Illustration 9	g01335384
Alignment of timing marks

6. Install idler gear (2) . Ensure that the timing marks on gear (1) and gear (2) are in alignment and that the mesh of the gears is correct. Refer to Disassembly and Assembly, "Idler Gear - Remove and Install". Check the end play of the idler gear. Refer to Specifications, "Gear Group (Front)" and refer to Disassembly and Assembly, "Idler Gear - Remove and Install" for further information.

7. Tighten bolt (6) for the camshaft gear to a torque of 95 N·m (70 lb ft). Check the end play of the camshaft gear. Refer to Specifications, "Camshaft" for more information.

8. Ensure that the fuel injection pump is locked in the correct position. Refer to Disassembly and Assembly, "Fuel Injection Pump - Install".

9. Install fuel injection pump gear (3) . Ensure that the timing marks on gear (2) and gear (3) are in alignment. See Illustration 9. Ensure that the mesh of the gears is correct. Refer to Disassembly and Assembly, "Fuel Injection Pump Gear - Install" for more information.

10. Remove Tooling (B) and (C) . Install plug (4) into hole (Y) in the cylinder block. Refer to Illustration 5.

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Illustration 10	g01335426
Checking backlash

11. Ensure that the backlash for gears (1) , (2) and (3) is within specified values. Refer to Specifications, "Gear Group (Front)" for further information.

12. Lubricate each gear with clean engine oil.

13. Adjust the engine valve lash. Refer to System Operation, Testing and Adjusting, "Engine Valve Lash - Inspect/Adjust".

End By:

1. Install the valve mechanism cover. Refer to Disassembly and Assembly, "Valve Mechanism Cover - Remove and Install".
2. Install the front cover. Refer to Disassembly and Assembly, "Front Cover - Remove and Install".