3608 Engine Caterpillar

Disassembly Procedure For The VTC 254 Turbocharger

Start By:

1. Remove the turbocharger. Refer to Disassembly and Assembly, "Turbocharger - Remove".

Illustration 1	g01294470

Note: Use 8T-0447 Dial Calipers to measure the dimensions in the following procedure.

Note: The following procedure shows a turbocharger that is removed from the engine. It is not always necessary to remove the turbocharger to perform this procedure.

Note: Refer to Disassembly and Assembly, "General Information (Reference Material)" for more information.

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Illustration 2	g00623402

1. Place the turbocharger in position on an appropriate work bench. Use a paint stick to mark the position of all the components of the turbocharger. This marking of the components will ease the assembly process.
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   Illustration 3	g01294227

2. Attach Tooling (R) and a suitable lifting device to elbow (1). The weight of elbow (1) is approximately 21 kg (46 lb). Remove bolts (2) and the washers. Remove elbow (1).
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   Illustration 4	g00623594

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   Illustration 5	g01298057

3. Attach Tooling (A) and a suitable lifting device to compressor housing (4). The weight of compressor housing (4) is approximately 95 kg (209 lb). Refer to Illustration 5.

4. Remove three bolts (3) and the washers.

5. Install Tooling (C). Refer to Illustration 5. Remove remaining bolts (3) and the washers. Remove bolts (5) and the washers.
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   Illustration 6	g01298061

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   NOTICE
   Do not allow the compressor housing to contact the impeller assembly during the removal procedure. Damage to the impeller assembly and the compressor housing may result.

6. Use bolts (3) as forcing screws, and remove compressor housing (4). Do not tilt the compressor housing. Damage could occur to impeller assembly (6).
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   Illustration 7	g01294253

7. Attach a suitable lifting device to bearing housing (8). The weight of bearing housing (8) is approximately 41 kg (90 lb). Remove bolts (7) and install Tooling (C).
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   Illustration 8	g00623663

8. Install bolts (7) as forcing screws and remove bearing housing (8).

   Note: Remove bearing housing (8) horizontally to prevent contact between the turbine blade and the ring cover.

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   Illustration 9	g00623684

9. Fasten Tooling (E) onto bearing housing (8) to place the rotating assembly in a horizontal position. Move bearing housing (8) to a flat surface.

10. Check the bearing clearance of the turbocharger in accordance with the following steps.

    1. Mount a magnetic base dial indicator on the bearing housing. Position the indicator tip against the end surface of the impeller hub.

    2. Move the turbine shaft toward the turbine end. Zero the dial indicator.

    3. Move the turbine shaft to the impeller end and observe the indicator reading. The clearance (end play) of the turbine shaft must be 0.100 to 0.300 mm (0.0039 to 0.0118 inch).
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       Illustration 10	g00623695

    4. Mount a magnetic base dial indicator on the bearing housing. Position the indicator tip against the impeller hub end diameter.

    5. Move the impeller end of the turbine shaft upward and move the turbine end downward. Zero the dial indicator.

    6. Move the impeller end of the turbine shaft downward and move the turbine end upward. Observe the indicator reading. The radial clearance of the bearing must be 0.440 to 0.870 mm (0.0173 to 0.0343 inch).

       Note: If the bearing clearances are not within the tolerance that is specified in the steps above, continue with Step 11 and the remainder of the procedure. If the bearing clearances are within the tolerance, go to Step 36 and continue with the remainder of the procedure.

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    Illustration 11	g00623721

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    Illustration 12	g00623729

11. Remove screw (9) and the washer from the inside of impeller assembly (6).

12. Use Tooling (B) and Tooling (D) to hold impeller assembly (6). Remove screw (9) with a socket wrench.
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    Illustration 13	g00623737

13. Install Tooling (F). Hold impeller assembly (6) with Tooling (B) and tighten Tooling (F) with an extension.
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    Illustration 14	g00623743

14. Install Tooling (G). Refer to Illustration 14.
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    Illustration 15	g00623749

15. Hold impeller assembly (6) with Tooling (B). Tighten Tooling (G) with a 1/4 inch Drive Extension and a Handle.
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    Illustration 16	g01294397

16. Install the following Tooling onto the impeller assembly: Tooling (H), Tooling (J), Tooling (K) and Tooling (L). Refer to Illustration 16.
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    Illustration 17	g01294490

17. Connect Tooling (M) and Tooling (N). Refer to Illustration 17. Apply pressure with Tooling (M) until the impeller assembly is free.
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    Illustration 18	g00623797

18. Disconnect Tooling (N). Remove the following Tooling: Tooling (L), Tooling (K), Tooling (J), Tooling (H) and Tooling (G). Remove impeller assembly (6) and Tooling (F) together.
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    Illustration 19	g00623825

19. Remove piston ring seal (10) from impeller assembly (6).

    Note: The maximum width of the seal ring groove in the turbine shaft is 2.85 mm (0.112 inch).

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    Illustration 20	g00623832

20. Remove socket head bolts (12) that secure cover (11).
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    Illustration 21	g00623857

21. Use socket head bolts (12) as forcing screws to remove cover (11).
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    Illustration 22	g00623866

22. Use socket head bolts (12) as forcing screws to remove compressor bearing assembly (13).
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    Illustration 23	g00623878

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    Illustration 24	g00623886

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    Illustration 25	g00623893

23. Remove socket head bolts (14).

24. Separate compressor bearing assembly (13).

25. Remove bushing (15). Measure the inside diameter of compressor bearing assembly (13). The maximum reusable bore diameter of the compressor bearing is 45.550 mm (1.7933 inch).

    Note: For additional information regarding the turbocharger, refer to Reuse and Salvage Guidelines, SEBF8092, "Specifications for Reusable Turbocharger Components on 3600 Family of Engines".

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    Illustration 26	g00624090

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    Illustration 27	g01294443

26. Use Tooling (P) and Tooling (Q) to remove thrust bearing (16).

27. Hold the body of Tooling (P) with Tooling (B) and Tooling (D). Refer to Illustration 27. Turn Tooling (Q) with a wrench in a clockwise direction to remove thrust bearing (16).
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    Illustration 28	g01294456

28. Remove thrust bearing (16) from Tooling (P).
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    Illustration 29	g00624108

29. Remove turbine (17) and the shaft assembly. Inspect turbine (17) and the shaft assembly.
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    Illustration 30	g00624118

30. Remove piston ring seal (18) from turbine (17) and the shaft assembly. Measure the following surfaces.

    1. The minimum outside diameter of the turbine shaft bearing (turbine end) is 42.980 mm (1.6921 inch).

    2. The minimum outside diameter of the turbine shaft (impeller end) is 33.480 mm (1.3181 inch).

    3. The minimum hub diameter is 6.00 mm (1.811 inch).

    4. The maximum width of the seal ring groove in the turbine shaft assembly is 2.85 mm (0.112 inch).
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       Illustration 31	g00624136

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       Illustration 32	g00624140

    5. Straighten the locking plates and remove bolts (20) that secure cover (19).

    6. Remove the carbon from the threaded holes. Use bolts (20) as forcing screws to remove cover (19).
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       Illustration 33	g00624147

    7. Use bolts (20) as forcing screws to remove cover assembly (21). Remove the O-ring seal from cover assembly (21).
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       Illustration 34	g00624152

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       Illustration 35	g00624157

    8. Remove socket head bolts (22) that hold turbine bearing assembly (23).

    9. Use socket head bolts (22) as forcing screws to remove turbine bearing assembly (23).
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    Illustration 36	g00624163

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    Illustration 37	g00624167

31. Remove socket head bolts (24) from turbine bearing assembly (23).

32. Separate turbine bearing assembly (23) and remove bushing (25).
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    Illustration 38	g00624173

33. Measure the inside diameter of turbine bearing assembly (23). The maximum reusable diameter for the turbine bearing is 55.060 mm (2.1677 inch).

    Note: For more information on the turbocharger, refer to Reuse and Salvage Guidelines, SEBF8092, "Specifications for Reusable Turbocharger Components on 3600 Family of Engines".

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    Illustration 39	g00624182

34. If damage is noted, remove cap (26) to perform an inspection. Be sure that the air passages are open.
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    Illustration 40	g01298832

35. Use a paint stick to mark the position of diffuser (27) in compressor housing (4). Remove the bolts that hold diffuser (27) to compressor housing (4).
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    Illustration 41	g00624202

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    Illustration 42	g00624197

36. Attach a suitable lifting device to gas inlet housing (30). The weight of gas inlet housing (30) is approximately 41 kg (90 lb). Remove bolts (29) and the washers and remove segments (28) that secure gas inlet housing (30) to the bearing housing (center section).

37. Remove gas inlet housing (30).
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    Illustration 43	g00624223

38. Remove the bolts and locking plates (31).

39. Remove ring cover (32).

40. Remove bolts (33) and the locking plates. Remove nozzle (34) from the gas inlet housing.

41. If necessary, remove cap (35).
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    Illustration 44	g00624229

42. Inspect nozzle (34). Replace the nozzle, if the nozzle is damaged.

43. Clean each part with clean solvent. Handle each part carefully to prevent damage to the parts. Dry the parts with compressed air.

44. Inspect the compressor bearing assembly. Inspect the turbine bearing assembly. If the radial clearance exceeds the limits, the bearings must be replaced. The tolerance of the radial clearance was determined when the bearing clearances were checked. Also replace the bearings if high wear is observed.

45. If the axial clearance exceeds permissible limits, the thrust bearing must be replaced. This axial clearance was determined when the clearances of the thrust bearing were checked. Also replace the thrust bearing if high wear is observed.

46. Inspect the impeller assembly. Replace the impeller assembly if the impeller assembly is damaged.

47. Replace all the O-ring seals and the piston ring seals.