M315D, M315D Series 2, M315D2, M317D Series 2 and M317D2 Wheeled Excavators Power Train Caterpillar

Assembly Procedure

Note: If the ring gear or the pinion shaft is damaged, both of the parts must be replaced as a set. The numbers on the ring gear and the numbers on the pinion shaft must mate. Do not use new bearings with used bearings in the differential. Mixing new bearings and used bearings will result in misalignment in the differential and the inability to accurately measure the rolling torque during the assembly.

Note: Correct measurements and torques are important when the differential is assembled. Incorrect measurements could cause incorrect tooth contact patterns in the differential. Incorrect measurements could cause a premature failure. Make sure that all surfaces are clean and free of oil or dirt prior to taking any measurement. Make sure that all surfaces are clean and free of oil or dirt prior to assembly.

Note: Cleanliness is an important factor. Before assembly, all parts should be thoroughly cleaned in cleaning fluid. Allow the parts to air dry. Wiping cloths or rags should not be used to dry parts. Lint may be deposited on the parts which may cause later trouble. Inspect all parts. If any parts are worn or damaged, use new parts for replacement.

Note: Check the O-ring seals, the gaskets, and the seals for wear or for damage. Replace the components, if necessary.

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Illustration 1	g01175936

1. Use a hammer and a punch to install spring pins (22) in differential case half (19). Install spring pins (22) in the original locations. Drive spring pins (22) into the differential case half until spring pins (22) bottom out. Make sure that the slots in spring pins (22) are in a circumferential position. Make sure that the slots in spring pins (22) are separated by 180 degrees.
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   Illustration 2	g01176327

2. Put ring gear (21) in a suitable press. Position differential case half (19) in the original location on ring gear (21). Align the spring pins in differential case half (19) with the four holes in ring gear (21). Use the suitable press to install differential case half (19) in ring gear (21). Make sure that differential case half (19) is firmly seated.

3. After ring gear (21) and differential case half (19) have been pressed together, install two bolts (14) that are 180 degrees from each other. Thread bolts (14) through differential case half (19) and into ring gear (21). Perform this operation at several locations in differential case half (19). This will ensure perfect alignment. This will also ensure that both halves of the differential will bolt together.
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   Illustration 3	g01175933

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   Illustration 4	g01176329

4. Install thrust washer (20) in differential case half (19). Make sure that the tab on thrust washer (20) is inserted into the corresponding notch in differential case half (19).

5. Install one of the two differential gears (17) on top of thrust washer (20). Apply a small amount of clean hydraulic oil on thrust washer (20) to allow easy movement during the assembly.
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   Illustration 5	g01175937

6. Assemble the spider gear assembly. Install bevel gears (24) on spider (25). Install thrust washers (23). Make sure that the tab on each thrust washer (23) is oriented upward. Lubricate thrust washers (23) and bevel gears (24) on spider (25) to allow easy movement during assembly.
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   Illustration 6	g01175931

7. Install spider gear assembly (18) in differential case half (19). Make sure that the tabs on thrust washers are oriented upward. Install differential gear (17).
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   Illustration 7	g01175930

8. Install thrust washer (16) in differential case half (15). Make sure that the tab on thrust washer (16) is inserted into the corresponding notch in differential case half (15).
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   Illustration 8	g01176331

9. Place differential case half (15) and differential case half (19) in a suitable press. Apply only enough pressure to allow both differential case halves to make contact. Note the alignment marks that were placed on both differential case halves during the disassembly.

   Note: If M16x1.5 bolts are used, apply Tooling (F) to bolts (14).

10. Install bolts (14). If M12x1.5 bolts are used, tighten bolts (14) to a torque of 145 N·m (105 lb ft). If M16x1.5 bolts are used, tighten bolts (14) to a torque of 300 N·m (221 lb ft).

    Note: Inspect the differential carrier closely. Make sure that the thrust washers are in place. Make sure that the differential gears and the bevel gears are free to move.

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    Illustration 9	g01176334

11. Raise the temperature of bearing cones (13). Install bearing cones (13) on differential assembly (10). Make sure that bearing cones (13) are seated against the shoulder of differential assembly (10).
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    Illustration 10	g01176629

12. Install shim (12). Use Tooling (C) to install bearing cup (11).
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    Illustration 11	g01176797

13. Use Tooling (E) and a depth micrometer to obtain Dimension (A).

14. Dimension (B) is equal to half the diameter of Tooling (E). Dimension (B) is 80.00 mm (3.1496 inch).

15. Add Dimension (A) and Dimension (B) to obtain Dimension (C).

16. Apply a marking compound to the ring gear.
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    Illustration 12	g01175889

17. Install differential assembly (10).
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    Illustration 13	g01176634

18. Use a depth micrometer to measure Dimension (D). Add 0.070 mm (0.0028 inch) to Dimension (D) for the bearing preload.

19. Add the corrected value for Dimension (D) to Dimension (E) on the ring gear. The sum of Dimension (D) and Dimension (E) is within the tolerance of Dimension (C). If necessary, adjust the thickness of shim (12) in Step 12.
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    Illustration 14	g02287013

20. Install bearing cup (8). Use a depth micrometer to determine Dimension (F).
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    Illustration 15	g02287093

21. Use a depth micrometer to determine Dimension (G).

22. Subtract Dimension (G) from Dimension (F). Add 0.150 mm (0.0059 inch) for bearing preload. This represents the required thickness for shim (9).
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    Illustration 16	g01176754

23. Install shim (9).
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    Illustration 17	g01176767

24. Use Tooling (C) to install bearing cup (8).
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    Illustration 18	g01175885

25. Use a suitable lifting device to position axle housing (6). The weight of axle housing (6) is approximately 84 kg (185 lb). Install bolts (7). Tighten bolts (7) to a torque of 390 N·m (288 lb ft).
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    Illustration 19	g01175882

26. Attach a suitable lifting device to transmission (1). The weight of transmission (1) is approximately 136 kg (300 lb). Position transmission (1) and install nuts (2). Tighten nuts (2) to a torque of 79 N·m (58 lb ft).
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    Illustration 20	g01176742

27. Use Tooling (D) to check the ring gear to pinion backlash. The required backlash for the 3070 is 0.15 to 0.27 mm (0.006 to 0.011 inch). The required backlash for the 3050 and the 3060 is 12 to 24 mm (0.005 to 0.01 inch). If necessary, adjust shims (12) and (9) to obtain the correct backlash.
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    Illustration 21	g01175882

28. Attach a suitable lifting device to transmission (1). The weight of transmission (1) is approximately 136 kg (300 lb). Remove nuts (2) and transmission (1).
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    Illustration 22	g01175885

29. Attach a suitable lifting device to position axle housing (6). The weight of axle housing (6) is approximately 84 kg (185 lb). Remove bolts (7) and axle housing (6).
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    Illustration 23	g01175889

30. Remove differential assembly (10).

31. Inspect the differential for the proper tooth pattern.
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    Illustration 24	g01018512
    Correct pinion distance on the driven side.

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    Illustration 25	g01018573
    Correct pinion distance on the driving side.

32. Refer to Illustrations 24 for the ideal tooth contact pattern.
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    Illustration 26	g01018575

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    Illustration 27	g01018576

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    Illustration 28	g01018574

33. Refer to Illustrations 26 and 27 for an incorrect tooth contact pattern. The pinion distance must be increased.
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    Illustration 29	g01018578

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    Illustration 30	g01018580

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    Illustration 31	g01018577

34. Refer to Illustrations 29 and 30 for an incorrect tooth contact pattern. The pinion distance must be decreased.

    Note: If the proper tooth pattern is not obtained, refer to Disassembly and Assembly, "Transmission - Assemble" to correct the tooth pattern.

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    Illustration 32	g01175889

35. Install differential assembly (10).
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    Illustration 33	g01175885

36. Use a suitable lifting device to position axle housing (6). The weight of axle housing (6) is approximately 84 kg (185 lb). Install bolts (7). Tighten bolts (7) to a torque of 390 N·m (288 lb ft).
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    Illustration 34	g01175884

37. Install axle shaft (5).
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    Illustration 35	g01175883

38. Attach a suitable lifting device to final drive and carrier (3). The weight of final drive and carrier (3) is approximately 29 kg (65 lb). Position final drive and carrier (3). Install bolts (4). Tighten bolts (4) to a torque of 280 N·m (207 lb ft).
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    Illustration 36	g01175882

39. Attach a suitable lifting device to transmission (1). The weight of transmission (1) is approximately 136 kg (300 lb). Position transmission (1) and install nuts (2). Tighten nuts (2) to a torque of 79 N·m (58 lb ft).

End By:

1. Install the rear axle.