966G and 972G Wheel Loaders Power Train Caterpillar

Installation 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 and this may cause later trouble. Inspect all parts. If any parts are worn or damaged, use new parts for replacement.

Note: If you heat the bearing cones, allow the parts to reach a uniform temperature. Then use a driver or a press to reset the bearing cones. Heat the bearing cones to a maximum of 135°C (275°F) for a maximum of four hours. Lubricate the bearing cones with SAE 30W gear oil after the bearing cones have cooled in order to prevent rust on the bearing cones.

Note: If you freeze the bearing cups, allow the parts to reach a uniform temperature. Then use a driver or a press to reset the bearing cups. The limit for freezing the bearing cups is -29°C (-20°F). Remove any frost and wipe the bearing cups dry. Lubricate the bearing cups with SAE 30W gear oil in order to prevent rust on the bearing cups.

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Illustration 1	g01017059

1. Raise the temperature of bevel gear (21) . Do not heat the bevel gear for more than four hours. Install bevel gear (21) on the differential assembly.

2. Apply Tooling (L) to bolts (20) and to the washer face. Install the washers and bolts (20) that hold bevel gear (21) in position. The torque for bolts (20) is 280 ± 40 N·m (205 ± 30 lb ft). Turn each bolt by an additional 120 ± 5 degrees. Make sure that the bevel gear is seated on the mating surface.

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NOTICE
A new differential group or a new case assembly will be equipped with bolts and washers that are used for shipping, assembly, and storage purposes only. Remove and discard these bolts and washers after the bevel gear has been installed. These bolts and washers should not be used for final assembly.

3. Press bearing cone (22) on the differential assembly.

4. Press bearing cone (19) on the differential assembly.

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Illustration 2	g00451865

5. Install bearing cup (17) , sleeve assembly (16) and locating pin (15) in differential housing (18) .

6. Apply lubricant to the threads on adjusting nut (14) . Install adjusting nut (14) in differential housing (18) . Do not install lock washer (13) and bolt (12) at this time.

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Illustration 3	g01017176

7. Install Tooling (C) on differential assembly (9) . Attach a suitable lifting device to Tooling (C) .

8. Use the suitable lifting device to install differential assembly (9) . The weight of the differential assembly is approximately 109 kg (240 lb).

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Illustration 4	g01017347

Note: Use the original shim pack or a new shim pack of the same thickness. If the original shim pack is not available, use 60 percent of a new shim pack.

9. Apply Tooling (J) to the O-ring seal before you install the O-ring seal on the pinion housing. Install Tooling (F) to the axle center housing. Install the shim pack on the pinion housing.

10. Install Tooling (B) on the pinion gear assembly. Attach a suitable lifting device to Tooling (B) .

11. Use the suitable lifting device to install pinion gear assembly (8) . The weight of the pinion gear assembly is approximately 66 kg (145 lb).

12. Install bolts (7) . The torque for bolts (7) is 300 ± 40 N·m (220 ± 30 lb ft).

    Note: The thickness of the shim pack may need to be changed when you adjust the tooth contact pattern.

13. Install the axle oil cooler. Refer to Disassembly and Assembly, "Heat Exchanger (Axle Oil Cooler) - Remove and Install".

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Illustration 5	g01021839

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Illustration 6	g01021794

14. Install bearing cup (6) , sleeve assembly (5) , and locating pin (4A) in intermediate housing (1) .

15. Apply lubricant to the threads on adjusting nut (3) . Install adjusting nut (3) in intermediate housing (1) . Do not install lock washer (4) and bolt (2) at this time.

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Illustration 7	g01017405

16. Fasten a suitable lifting device to intermediate housing (1) . Use the suitable lifting device to install intermediate housing (1) . Install the three bolts that hold the intermediate housing to the axle center housing.

17. Position the axle center housing horizontally on Tooling (A) .

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Illustration 8	g01021888

18. Use Tooling (F) and Tooling (G) to tighten adjusting nuts (3) and (14) to a position which maintains gear backlash and slight bearing end play.

19. Measure the torque that is required to rotate the pinion shaft. Record the measured torque. Use Tooling (K) on the pinion shaft nut for this measurement.

20. While you are rotating the pinion shaft back and forth, tighten adjusting nut (14) to the zero backlash position. Then back off adjusting nut (14) by 20 degrees plus the increment to the nearest lock position.

21. Tighten adjusting nut (3) while you are rotating the pinion shaft. Tighten nut (3) until the torque is increased by 0.2 to 0.6 N·m (2.0 to 5.0 lb in) over the torque that was recorded in Step 19. This is the seated position.

22. Tighten adjusting nut (3) to the nearest lock position.

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Illustration 9	g00315693
(A) Distance of dial indicator from pinion centerline.

Note: To ensure correct assembly and correct adjustment, measure the rolling torque of the bevel gear group at the pinion shaft. For new bearings, the rolling torque should be 4.5-6.8 N·m (40-60 lb in). For used bearings, the rolling torque should be 0.9 to 1.8 N·m (8 to 16 lb in).

23. Place a dial indicator tangent to the spline, as shown. Make sure that the yoke or the spline adapter is tight to the spline. Measure the backlash between bevel gear (21) and the pinion shaft. The backlash must be 0.28 ± 0.13 mm (0.011 ± 0.005 inch).

    The following chart gives examples of backlash at the pinion shaft by showing the different distances from the pinion centerline to the dial indicator.

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    Table 2

    Examples of Backlash at Pinion Shaft
    Dimension (A)	Nominal Backlash	Maximum Backlash	Minimum Backlash
    50 mm (2 inch)	0.28 mm (.011 inch)	0.40 mm (.016 inch)	0.18 mm (.007 inch)
    100 mm (4 inch)	0.55 mm (.022 inch)	0.80 mm (.032 inch)	0.35 mm (.014 inch)
    150 mm (6 inch)	0.83 mm (.033 inch)	1.20 mm (.047 inch)	0.53 mm (.021 inch)
    200 mm (8 inch)	1.10 mm (.043 inch)	1.60 mm (.063 inch)	0.70 mm (.028 inch)

24. If the backlash does not meet the specifications, loosen one adjusting nut and tighten the opposite adjusting nut by the same amount. This will maintain the bearing preload.

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

26. Install lock washer (4) and bolt (2) in adjusting nut (3) . Do not bend lock washer (4) at this time.

27. Install lock washer (13) and bolt (12) in adjusting nut (14) . Do not bend bolt lock at this time.

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Illustration 10	g00315875

28. After the backlash adjustment and the preload adjustment have been made, the tooth contact between the pinion shaft and bevel gear (21) 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 (21) .

    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. Illustration 10 is an example of the correct area of tooth contact.

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Illustration 11	g00315877

29. If the tooth contact looks like the marks in Illustration 11, perform the following procedure:

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

    2. Repeat Steps 21 through 23 for the backlash adjustment.

    3. Repeat Step 24.

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Illustration 12	g00315878

30. If the tooth contact looks like the marks in Illustration 12, perform the following procedure:

    1. Add shims behind the pinion housing.

    2. Repeat Steps 21 through 23 for the backlash adjustment.

    3. Repeat Step 24.

       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.

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

32. Install lock washer (4) and bolt (2) in adjusting nut (3) .

33. Install lock washer (13) and bolt (12) in adjusting nut (14) .

34. Bend the locks.

35. Install the service brakes. Refer to Disassembly and Assembly, "Service Brakes - Remove and Install".

End By:

1. Install the rear oscillating axle. Refer to Disassembly and Assembly, "Oscillating Axle (Rear) - Remove and Install".
2. Install the front fixed axle. Refer to Disassembly and Assembly, "Fixed Axle (Front) - Remove and Install".