2004/09/27 Caterpillar

Landfill Compactor:

826GSeries II (S/N: AYH1-UP)

826G (S/N: 7LN1-UP)

Soil Compactor:

825GSeries II (S/N: AXB1-UP)

825G (S/N: 6RN1-UP)

Wheel Dozer:

824GSeries II (S/N: AWW1-UP)

824G (S/N: 4SN1-UP)

Wheel Loader:

980GSeries II (S/N: AXG1-UP; AWH1-UP; AYT1-UP)

980G (S/N: 9CM1-UP; 2KR1-UP; 2SR1-UP)

Disassembly and Assembly, SENR1330, "824G Wheel Dozer, 825G Soil Compactor, and 826G Landfill Compactor Power Train", "Differential and Bevel Gear - Assemble". This module is part of Service Manual, SENR1325.Disassembly and Assembly, RENR6029, "824G Series II Wheel Dozer, 825G Series II Soil Compactor, and 826G Series II Landfill Compactor Power Train", "Differential and Bevel Gear - Assemble". This module is part of Service Manual, RENR6020.Disassembly and Assembly, SENR5877, "980G Wheel Loader Power Train", "Differential and Bevel Gear - Assemble". This module is part of Service Manual, SENR5870.Disassembly and Assembly, RENR4378, "980G Series II Wheel Loader Power Train", "Differential and Bevel Gear - Assemble". This module is part of Service Manual, RENR6000.

A portion of the existing assembly procedure has been changed. Replace Steps 48 through 62 with the following information.

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Illustration 1	g00526501

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Illustration 2	g00526500

48. 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 3	g00528785

49. 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.

50. 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.

51. 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 49.

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Illustration 4	g00528844

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Illustration 5	g00528846

52. 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).

53. 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 6	g00315875

54. 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 6 for the correct area of tooth contact.

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Illustration 7	g00315877

55. If the tooth contact looks like the marks in Illustration 7, perform the following procedure:

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

    2. Repeat Steps 52 through 54 for the backlash adjustment.

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Illustration 8	g00315878

56. If the tooth contact looks like the marks in Illustration 8, perform the following procedure:

    1. Add shims behind the pinion housing.

    2. Repeat Steps 52 through 54 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.

57. 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 9	g00528859

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

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Illustration 10	g00528861

59. Tighten two 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 11	g00528939

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Illustration 12	g00528940

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