C7.1 Industrial Engine Gear Group (Front) - Remove and Install - Heavy Duty Gear Group (Front) Caterpillar

Removal Procedure

Start By:

1. Remove the front cover. Refer to Disassembly and Assembly, "Front Cover - Remove and Install" 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: 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. If the air compressor is equipped with a hydraulic pump, remove the hydraulic pump. Refer to Original Equipment Manufactures (OEM) for the correct procedure.

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

3. If the engine is equipped with only a hydraulic pump, remove the hydraulic pump. Refer to the OEM for the correct procedure.

4. 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" for the correct procedure.

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

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   Illustration 1	g02048654

5. Remove plug (2) from the cylinder block. Remove O-ring seal (1) from the plug.

6. 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" for the correct procedure. Install Tooling (D) through Hole (W) in order to lock the crankshaft.

7. Remove Tooling (D).

8. Use Tooling (A) in order to rotate the crankshaft in a clockwise direction and position the crankshaft at 60 degrees after top dead center.
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   Illustration 2	g02048655

9. Loosen threaded inserts (4) on all rocker arms (3). Unscrew threaded inserts (4) on all rocker arms (3) until all valves are fully closed. Ensure that guides (5) for the pushrods are left in position on threaded inserts (4).

   Note: Ensure that ALL threaded inserts are fully unscrewed.

10. 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" for the correct procedure. Install Tooling (D) through Hole (W) in order to lock the crankshaft. Refer to Illustration 1.
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    Illustration 3	g02048653

11. Install Tooling (B) through Hole (X) in camshaft gear (6) 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" for the correct procedure.

12. Use Tooling (C) in order to lock the fuel injection pump gear in the correct position. Refer to Disassembly and Assembly, "Fuel Injection Pump - Remove" for the correct procedure.

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

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    Illustration 4	g02052394

13. If the right-hand side of the engine is equipped, with a hydraulic pump remove the hydraulic pump. Refer to the OEM for the correct procedure.

14. If necessary, remove bolts (7) from plate (8). Remove plate (8) and remove O-ring seal (9).

15. Remove circlip (10) and remove gear assembly (11) from front housing (12).
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    Illustration 5	g02053673

16. If necessary, follow Step 16.a through Step 16.b in order to disassemble gear assembly (11).

    1. Remove circlip (13) from gear (15).

    2. Place gear assembly (11) on a suitable support. Press bearing (14) from gear (15).
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    Illustration 6	g02048714

17. Mark gear (6), gear (16), gear (17) and gear (18) in order to show alignment. Refer to Illustration 6.

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

18. Remove camshaft gear (6). Refer to Disassembly and Assembly, "Camshaft Gear - Remove and Install" for the correct procedure.
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    Illustration 7	g02053984

19. Remove bolts (22) and bolts (24).

20. Remove tube assembly (23) from idler gear (16) and idler gear (26).

21. Remove plate (21).

22. Remove idler gear (16) from front housing (12).

23. Remove idler gear (26) and idler gear hub (25) from front housing (12).

24. Remove hub (20) (not shown) from front housing (12).

25. If necessary, remove bearing (19) from front housing (12). Refer to Disassembly and Assembly, "Housing (Front) - Remove" for the correct procedure.

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" for the correct procedure.
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   Illustration 8	g02048656

2. If necessary, install Tooling (D) into Hole (W) in the cylinder block. Use Tooling (D) 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 (D). Do not use Tooling (D) to hold the crankshaft during repairs.

3. Ensure that all of the components of the front gear group are clean and free from wear and damage. If necessary, replace any components that are worn or damaged.
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   Illustration 9	g02048660

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   Illustration 10	g02053693

4. If necessary, install bearing (19) to front housing (12). Refer to Disassembly and Assembly, "Housing (Front) - Install" for the correct procedure.

5. Install hub (20) to the recess of front housing (12). Ensure that oil Hole (Y) is to the top of the hub.

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

7. Lubricate idler hub (20) with clean engine lubricating oil. Install idler gear (16) to the idler hub. Ensure that the timing marks are toward the front of the idler gear. Align timing marks on idler gear (16) with gear (17) and gear (18).

8. Lubricate idler gear hub (25) with clean engine lubricating oil and install idler gear (26) to the idler gear hub. Install the assembly for idler gear (26) to front housing (12).

   Note: Ensure that the idler gear hub and the idler gear are correctly aligned.

9. Position plate (21) onto idler gear (16).

   Note: Ensure that the identification mark TOP is upward.

10. Position tube assembly (23) onto idler gear (16) and idler gear (26). Install bolts (22) and bolts (24).

    Note: Ensure that the tube is correctly positioned on the hubs of the idler gears.

11. Tighten bolts (22) and bolts (24) to a torque of 44 N·m (32 lb ft).
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    Illustration 11	g02048659

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    Illustration 12	g02048653

12. Install camshaft gear (6). Loosely install bolt (28) and washer (27) for the camshaft gear. Refer to Disassembly and Assembly, "Camshaft Gear - Remove and Install" for the correct procedure.

13. Install Tooling (B) through Hole (X) in camshaft gear (6) into the front housing.
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    Illustration 13	g02353398

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    Illustration 14	g02353397

14. Ensure that the timing marks on gear (6), gear (16), gear (17) and gear (18) are in alignment.

15. Remove Tooling (B), Tooling (C), and Tooling (D).

16. When a 8.8 Graded bolt (28) is installed. Tighten the bolt to a torque of 95 N·m (70 lb ft).

    When a 10.9 Graded bolt (28) is installed. Tighten the bolt to a torque of 120 N·m (89 lb ft).

17. Use Tooling (E) in order to check the end play of the camshaft gear. Refer to Specifications, "Camshaft" for more information.

18. Use Tooling (E) in order to check the end play of the idler gears. Refer to Specifications, "Gear Group (Front)" and refer to Disassembly and Assembly, "Idler Gear - Remove and Install" for more information.

19. Use Tooling (E) in order to measure the backlash for gear (6), gear (16), gear (17) and gear (18). Refer to Specifications, "Gear Group (Front)" for more information.
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    Illustration 15	g02058193

20. If necessary, follow Step 20.a through Step 20.c in order to assemble gear assembly (11).

    1. Apply a small continuous bead of Tooling (F) to inner Surface (Z) of bearing (14). Place the inner race of bearing (14) onto a suitable support. Press the shaft of gear (15) into bearing (14) until the shoulder of the gear is against the bearing. Remove any excess bearing mount compound.

    2. Install circlip (13) to gear (15).

    3. Lightly lubricate bearing (14) and gear (15) with clean engine oil.
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    Illustration 16	g02052394

21. Install gear assembly (11) to front housing (12). Ensure that the shaft of gear assembly (11) is correctly aligned with the bearing in front housing (12).

22. Install circlip (10) to front housing (12).

    Note: Ensure that the circlip is correctly located in the front housing.

23. Ensure that there is tactile backlash between the idler gear and the accessory drive gear.

24. If the right-hand side of the engine is equipped, with a hydraulic pump install the hydraulic pump. Refer to the OEM for the correct procedure.

25. Lightly lubricate a new O-ring seal (9) with Tooling (G). Install new O-ring seal (9) to plate (8). Install plate (8) to front housing (12).

26. Install bolts (7) to plate (8). Tighten the bolts to a torque of 16 N·m (142 lb in).

27. Lubricate each gear with clean engine oil.
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    NOTICE
    Failure to ensure that the crankshaft is positioned at 60 degrees after top dead center will result in interference between the pistons and the valves. Interference between the pistons and the valves will result in damage to the engine.

28. Use Tooling (A) in order to rotate the crankshaft in a clockwise direction and position the crankshaft at 60 degrees after top dead center.
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    Illustration 17	g02048655

29. Ensure that guides (5) for the pushrods are correctly positioned on threaded inserts (4). Tighten threaded inserts (4) on all rocker arms (3). Tighten the threaded inserts to a torque of 30 N·m (265 lb in).

    Note: When the threaded insert is tightened, the threaded insert must be seated correctly into the cup for the pushrod.

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    Illustration 18	g02048654

30. Install a new O-ring seal (1) to plug (2). Install the plug into Hole (W) in the cylinder block. Tighten plug (2) to a torque of 21 N·m (186 lb in).

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

32. If the air compressor is equipped with a hydraulic pump, install the hydraulic pump. Refer to the OEM for the correct procedure.

33. If the engine is equipped only with a hydraulic pump, install the hydraulic pump. Refer to the OEM for the correct procedure.

34. The engine should not be operated for a period 30 minutes after the threaded inserts on all the rocker arms have been tightened. This period will allow the force from the valve springs to purge off excessive engine oil from the hydraulic lifters.

End By:

1. Install the front cover. Refer to Disassembly and Assembly, "Front Cover - Remove and Install" for the correct procedure.

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