C6.6 Engines for Caterpillar Built Machines Idler Gear - Remove Caterpillar

Removal Procedure (Standard Idler Gear)

Start By:

1. Remove the fuel injection pump gear. Refer to Disassembly and Assembly, "Fuel Pump Gear - Remove" for the correct procedure.

2. Remove the valve mechanism cover. Refer to Disassembly and Assembly, "Valve Mechanism Cover - Remove and Install" for the correct procedure.

Note: Care must be taken in order to ensure that the fuel injection pump timing is not lost during the removal of the fuel pump gear. Carefully follow the procedure in order to remove the fuel pump gear.

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Illustration 1	g01337918
Alignment of timing marks

1. Ensure that Tooling (A) is installed into Hole (X) in the camshaft gear. Use Tooling (A) in order to lock the camshaft in the correct position.

   Note: Ensure that the gears are marked in order to show alignment. Refer to Illustration 1.

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   Illustration 2	g01337919

2. Ensure that Tooling (B) is installed in Hole (Y) in the cylinder block. Use Tooling (B) in order to lock the crankshaft in the correct position.
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   Illustration 3	g01337921

3. Loosen nuts (5) on all rocker arms (6). Unscrew adjusters (4) on all rocker arms (6) 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.

4. Mark plate (3) in order to show orientation.

   Note: Identification will ensure that the plate can be installed in the original orientation.

5. Remove bolts (1).

6. Remove plate (3).
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   Illustration 4	g01337922

7. Remove the assembly of idler gear (2) and hub (7) from the recess in the front housing.

   Note: The idler gear must be tilted during removal.

8. Remove hub (7) from idler gear (2).

Removal Procedure (Early Heavy-Duty Idler Gear)

Start By:

1. Remove the fuel injection pump gear. Refer to Disassembly and Assembly, "Fuel Pump Gear - Remove" for the correct procedure.

2. Remove the valve mechanism cover. Refer to Disassembly and Assembly, "Valve Mechanism Cover - Remove and Install" for the correct procedure.

Note: Care must be taken in order to ensure that the fuel injection pump timing is not lost during the removal of the fuel pump gear. Carefully follow the procedure in order to remove the fuel pump gear.

Note: The assembly of heavy-duty idler gear is not serviceable. Do not disassemble the heavy-duty idler gear.

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Illustration 5	g01337924
Alignment of timing marks

1. Ensure that Tooling (A) is installed into hole (X) in the camshaft gear. Use Tooling (A) in order to lock the camshaft in the correct position.

   Note: Ensure that the gears are marked in order to show alignment. Refer to Illustration 5.

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   Illustration 6	g01337919

2. Ensure that Tooling (B) is installed in hole (Y) in the cylinder block. Use Tooling (B) in order to lock the crankshaft in the correct position.
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   Illustration 7	g01337921

3. Loosen nuts (4) on all rocker arms (5). Unscrew adjusters (3) on all rocker arms (5) 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.

4. Remove bolts (1) from the assembly of heavy-duty idler gear (2).
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   Illustration 8	g01337922

5. Remove the assembly of idler gear (2) from the recess in the front housing.

   Note: The idler gear must be tilted during removal.

Removal Procedure (Latest Heavy-Duty Idler Gear)

Start By:

1. If the engine is equipped with an air compressor, remove the air compressor. Refer to Disassembly and Assembly, "Air Compressor - Remove and Install" for the correct procedure.

2. If the engine is equipped with an accessory drive, remove the accessory drive. Refer to Disassembly and Assembly, "Accessory Drive - Remove and Install" for the correct procedure.

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

4. Remove the valve mechanism cover. Refer to Disassembly and Assembly, "Valve Mechanism Cover - Remove and Install" for the correct procedure.

Note: Care must be taken in order to ensure that the fuel injection pump timing is not lost during the removal of the fuel pump gear. Carefully follow the procedure in order to remove the fuel pump gear.

Note: The assembly of heavy-duty idler gear is not serviceable. Do not disassemble the heavy-duty idler gear.

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Illustration 9	g01343977
Alignment of timing marks

1. Ensure that Tooling (A) is installed into Hole (X) in the camshaft gear. Use Tooling (A) in order to lock the camshaft in the correct position.

   Note: Ensure that the gears are marked in order to show alignment. Refer to Illustration 9.

2. Ensure that Tooling (B) is installed in Hole (Y) in the front housing. Use Tooling (B) in order to lock the crankshaft in the correct position.
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   Illustration 10	g01337921
   Typical example

3. Loosen nuts (5) on all rocker arms (6). Unscrew adjusters (4) on all rocker arms (5) 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.

4. Remove bolts (1) from the assembly of heavy-duty idler gear (2). Refer to Illustration 9.
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   Illustration 11	g01269933
   Typical example

5. Remove the assembly of idler gear (2) from the recess in the front housing.

   Note: The idler gear must be tilted during removal.

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   Illustration 12	g01348835
   Typical example

6. If necessary, remove plate (6). Install Tooling (C) into threaded Hole (Z) in order to remove plate (6).