980G Wheel Loader Power Train Caterpillar

Assembly Procedure

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.

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Illustration 1	g00527394

1. Use the proper equipment to handle bearing cone (43) . Heat bearing cone (43) to a maximum temperature of 135 °C (275 °F). Install bearing cone (43) on case assembly (33) .

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Illustration 2	g00527427

2. Heat the bevel gear to a temperature between 70 °C (160 °F) and 120 °C (250 °F) in order to install the bevel gear to the differential case assembly. Install two M20X2.5 threaded guide pins (45) in the bevel gear (44) , as shown.

3. Attach a suitable lifting device to case assembly (33) . Use the lifting device to carefully install case assembly (33) to bevel gear (44) . The weight of case assembly (33) is approximately 39 kg (86 lb).

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Illustration 3	g00527113

4. Install four new bolts (42) and new washers that are equally spaced. Tighten bolts (24) between 70 N·m (50 lb ft) and 100 N·m (75 lb ft). Ensure that bevel gear (44) is properly seated to case assembly (33) . Loosely, install 20 new bolts (42) and new washers. After the bevel gear has cooled to 50 °C (120 °F) or less, loosen four tightened bolts (42) . Use an alternating sequence and mark each bolt as the bolts are tightened. Tighten the 24 bolts to a torque of 130 ± 10 N·m (95 ± 7 lb ft). After the 24 bolts have been torqued, turn the bolts to an additional 120 degrees.

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Illustration 4	g00527087

5. Turn the differential and bevel gear to the opposite end. Install thrust washer (41) and gear (40) in case assembly (33) .

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Illustration 5	g00527035

6. Install sleeve bearings (37) , gears (38) and thrust washers (39) on spider (36) .

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Illustration 6	g00527007

7. Install spider (36) and the gear assemblies in case assembly (33) .

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Illustration 7	g00527000

8. Install gear (35) in the case assembly.

9. Install thrust washer (34) on gear (35) .

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Illustration 8	g00526993

Note: Align the marks on case (32) and case assembly (33) .

10. Install case (32) on case assembly (33) .

11. Install bolts (31) and the washers. Tighten bolts (31) to a torque of 270 ± 40 N·m (200 ± 30 lb ft).

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Illustration 9	g00527535

12. Use the proper equipment to handle bearing cone (30) . Heat bearing cone (30) to a maximum temperature of 135 °C (275 °F). Install bearing cone (30) on case (32) .

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Illustration 10	g00527575

13. Install O-ring seal (17) on the pinion housing.

14. Use the proper equipment to handle bearing cup (16) . Lower the temperature of bearing cup (16) . Install bearing cup (16) in the pinion housing, as shown.

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Illustration 11	g00527580

15. Use the proper equipment to handle bearing cup (15) . Lower the temperature of bearing cup (15) . Turn the pinion housing to the opposite end. Install bearing cup (15) in the pinion housing, as shown.

Note: Allow the bearing cups and the pinion housing to reach a uniform temperature.

16. Use a suitable driver to reset the bearing cups. This will ensure that the bearing cups are seated against the shoulders of the pinion housing.

17. Apply clean oil to the bearing cups.

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Illustration 12	g00527598

18. Use the proper equipment to handle bearing cone (13) . Heat bearing cone (13) to a maximum temperature of 135 °C (275 °F). Install bearing cone (13) on pinion shaft (10) .

Note: Allow the bearing cone and the pinion shaft to reach a uniform temperature.

19. Use a hammer and a punch to reset the bearing cone around the inside race of the bearing. This will ensure that the bearing cone is seated against the shoulder of the pinion shaft.

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Illustration 13	g00527614

20. Apply clean oil to bearing cone (13) .

21. Fasten Tooling (B) and a suitable lifting device to the pinion housing, as shown. Lower the pinion housing on the pinion shaft.

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Illustration 14	g00527624

22. Use the proper equipment to handle bearing cone (14) . Heat bearing cone (14) to a maximum temperature of 135 °C (275 °F). Install bearing cone (14) on pinion shaft (10) .

    Note: DO NOT reset bearing cone (14) at this time.

23. Apply clean oil to bearing cone (14) .

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Illustration 15	g00524859

24. Install washer (11) on pinion shaft (10) .

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Illustration 16	g00527655

25. Install retaining nut (9) on pinion shaft (10) .

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Illustration 17	g00524858

26. Use Tooling (C) to tighten retaining nut (9) in order to load the bearings.

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Illustration 18	g00528018

27. Attach Tooling (G) to yoke assembly (1) . Install yoke assembly (1) and Tooling (G) on the pinion shaft.

28. Use a torque wrench and Tooling (G) to slowly turn the pinion shaft. Check the rolling torque.

    Note: The proper rolling torque is 1.2 to 3.4 N·m (10.68 to 30.26 lb in) for new bearings. If the existing bearings are used, limit the rolling torque to half of the specification.

    Note: If the rolling torque exceeds the specification, back off the shaft by a 1/8 turn. Reseat the bearings and repeat Steps 27 and 28.

    Note: Use 0.6 to 1.7 N·m (5.34 to 15.13 lb in) preload torque for machines with more than 100 hours of operation.

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Illustration 19	g00524857

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Illustration 20	g00528192
Completed Stake (H) The spherical radius of the tool for peening must be 7.5 to 8.0 mm (0.295 to 0.315 inch). (J) The acceptable angle of the tool for peening is 20 ± 10 degrees. (K) The minimum length of the crimp is 4.7 mm (0.185 inch). (L) The minimum depth of the crimp is 2.5 mm (0.098 inch). (M) Top view

Note: Before you stake the nut, make sure that the pinion shaft has zero end play.

29. When the rolling torque is correct, stake nut (9) by peening the collar in the slot in pinion shaft (10) . See Illustration 20 and the caption for the correct dimensions.

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Illustration 21	g00528240

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Illustration 22	g00528241

30. Use Tooling (E) to install lip seal (8) in retainer (6) . Make sure that the sealing lip is facing inward. Apply clean oil to the lip seal.

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Illustration 23	g00528246

31. Install O-ring seal (7) on the opposite side of retainer (6) .

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Illustration 24	g00524855

32. Install retainer (6) on the pinion housing.

33. Install Tooling (B) on the pinion housing, as shown. Install four bolts (5) and the washers.

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Illustration 25	g00526567

34. Install Tooling (F) and a suitable lifting device to differential and bevel gear (28) . Install differential and bevel gear (28) to carrier (29) . The weight of the differential and bevel gear is 130 kg (285 lb).

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Illustration 26	g00526558

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Illustration 27	g00526556

35. Apply clean oil to bearing cups (26) and (27) . Install bearing cups (26) and (27) in the carrier assembly, as shown.

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Illustration 28	g00526553

36. Install bearing cap (25) , bolts (24) and the washers. DO NOT tighten bolts (24) at this time.

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Illustration 29	g00526503

37. Install bearing cap (23) , bolts (22) and the washers. DO NOT tighten bolts (22) at this time.

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Illustration 30	g00526501

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Illustration 31	g00526500

38. Install adjustment rings (20) and (21) in each side of the differential.

39. Tighten bolts (22) and (24) to a torque of 25 N·m (18 lb ft). This will allow adjustment rings (20) and (21) to move freely.

    Note: Adjust the bearing preload and the gear backlash after the pinion housing has been installed.

40. Use a suitable lifting device to reposition the carrier on Tooling (A) . The weight of the carrier and the differential assembly is 305 kg (670 lb).

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Illustration 32	g00524854

Note: If the pinion housing or the carrier housing are being replaced, install 80 percent of a new shim pack as a starting point for the pinion depth adjustment.

41. Install original shim pack (4) between the carrier and the pinion housing.

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Illustration 33	g00524853

42. Use a suitable lifting device to carefully install pinion housing (3) on the carrier, as shown.

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Illustration 34	g00524795

Note: Do not reuse old bolts (2) . Discard old bolts (2) and install new bolts.

Note: For the no-spin differential on 826G Landfill Compactor and 980G Wheel Loader, tighten bolts (2) to a torque of 105 ± 20 N·m (75 ± 15 lb ft) plus an additional 120 degrees ± 10 degrees. For the standard differential, tighten bolts (2) to a torque of 270 ± 40 N·m (200 ± 30 lb ft).

43. Make sure that backlash is present prior to securing pinion housing (3) to the carrier. Install sixteen bolts (2) and the washers. Tighten bolts (2) to the specification that is called out in the above note.

44. Replace Tooling (B) with bolts (5) and the washers.

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Illustration 35	g00528713

45. Install yoke assembly (1) on the pinion shaft.

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Illustration 36	g00526501

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Illustration 37	g00526500

46. Move adjustment rings (20) and (21) on the carrier to a position that maintains gear backlash and slight bearing end play.

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Illustration 38	g00528785

47. Install Tooling (G) on yoke assembly (1) , as shown. Use a torque wrench and Tooling (G) to slowly turn yoke assembly (1) . Check the overall rolling torque with no bearing load on the differential bearings. Record the measured torque.

48. Oscillate the bevel gear and advance adjustment ring (20) . Continue to advance the adjustment ring until there is no backlash. Back off the adjustment ring by 2 lugs to the nearest locking position.

49. Advance adjustment ring (21) and check the rolling torque on the pinion shaft. Continue to advance the adjustment ring until the rolling torque is 0.5 to 1.7 N·m (4.4 to 15.0 lb in) greater than the torque value that was measured in Step 47.

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Illustration 39	g00528844

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Illustration 40	g00528846

50. Mount Tooling (D) on the carrier, as shown. Measure the backlash at four places on the bevel gear at 90 degree intervals. Compare the lowest reading to the specifications. The proper backlash setting is 0.36 ± 0.13 mm (.014 ± 0.005 inch).

51. If the backlash is not within the specification, retract one adjustment ring and advance the opposite adjustment ring equally. This will maintain the bearing preload. Recheck the bearing preload.

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Illustration 41	g00315875

52. After the backlash adjustment and the preload adjustment have been made, the tooth contact between the pinion shaft and bevel gear (41) must be checked. Use the following procedure:

    1. Put a small amount of Prussian blue, red lead, or paint on three or four adjacent teeth of bevel gear (41) .

    2. Rotate the pinion shaft for several revolutions in one direction. Then rotate the pinion shaft for several revolutions in the opposite direction. Then turn the pinion shaft in the original direction in order to observe the marked teeth.

    3. The correct area of tooth contact begins near the inside end of the teeth. The contact area should extend to a maximum of 50 percent of the length of the teeth. See Illustration 41 for the correct area of tooth contact.

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Illustration 42	g00315877

53. If the tooth contact looks like the marks in Illustration 42, perform the following procedure:

    1. Remove some of the shims that are behind the pinion housing.

    2. Repeat Steps 50 through 52 for the backlash adjustment.

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Illustration 43	g00315878

54. If the tooth contact looks like the marks in Illustration 43, perform the following procedure:

    1. Add shims behind the pinion housing.

    2. Repeat Steps 50 through 52 for the backlash adjustment.

       Note: Always make sure that the backlash adjustment is correct before an adjustment is made to the area of tooth contact. Several adjustments to the backlash and to the tooth contact may be necessary in order to achieve the correct adjustments. A change to gear backlash will also change the gear contact and vice versa.

55. After the adjustments are made, remove any dyes or paint from the gears.

Note: When the proper backlash has been obtained, tighten the bearing cap bolts. The bearing cap bolts have different torque values. Make sure that the proper torque is applied.

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Illustration 44	g00528859

56. Tighten bearing cap bolts (22) to a torque of 1800 ± 200 N·m (1320 ± 150 lb ft).

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Illustration 45	g00528861

57. Tighten bearing cap bolts (24) to a torque of 900 ± 100 N·m (660 ± 75 lb ft).

    Note: Expect the rolling torque to increase by 0.5 to 1.2 N·m (4.4 to 10.6 lb in) after the bearing cap bolts are tightened.

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Illustration 46	g00528939

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Illustration 47	g00528940

58. Install bearing locks (18) and (19) and the bolts on bearing caps, as shown.

End By: Install the differential and bevel gear. Refer to Disassembly and Assembly, "Differential and Bevel Gear - Install" for the machine that is being serviced.