IT38G Integrated Toolcarrier and 938G Wheel Loader Power Train Caterpillar

Assembly Procedure

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Illustration 1	g00733587

1. Use bolts of a suitable size to fasten the rim of the axle to Tooling (B) .

2. Heat outer bearing cone (17) to a maximum temperature of 135 °C (275 °F).

3. Install the bearing cone (17) on the axle shaft, as shown. The bearing cone should be seated against the shoulder of the axle shaft.

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

4. Use a suitable driver or a press to reset the bearing cone. This will ensure that the bearing cone is seated properly.

5. Apply a thin coat of clean SAE 30 oil on bearing cone (17) .

   Note: Make sure that the rubber seals and all surfaces that contact the seals are clean and dry. After installation of the seals, apply clean SAE 30 oil on the contact surfaces of the metal seals.

6. Use Tooling (E) to install the Duo-Cone (15) seal in the axle assembly. Refer to Disassembly and Assembly, "Duo-Cone Conventional Seals - Install" for the correct procedure.

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Illustration 2	g00733611

7. Lower the temperature of bearing cup (16) . Install the bearing cup (16) in the end of the axle housing. Make sure that the bearing cup is seated with the mating surface.

Note: Allow the bearing cup (16) and the axle to reach a uniform temperature.

8. Use a suitable driver or a press to reset bearing cup (16) . This will ensure that the bearing cup (16) is seated properly.

Note: Make sure that the rubber seals and all surfaces that contact the seals are clean and dry. After the installation of the seals, apply clean SAE 30 oil on the contact surfaces of the metal seals.

9. Use Tooling (E) to install Duo-Cone seal (15) in the end of the axle housing. Refer to Disassembly and Assembly, "Duo-Cone Conventional Seals - Install" for the correct procedure.

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Illustration 3	g00733620

10. Lower the temperature of inner bearing cup (13) . Install the bearing cup (13) in the opposite end of the axle housing, as shown. Make sure that the bearing cup is seated on the mating surface.

Note: Allow bearing cup (13) and the axle to reach a uniform temperature.

11. Use a suitable driver or a press to reset bearing cup (13) . This will ensure that bearing cup (13) is seated properly.

Note: The following steps are for the installation of ring gear (14) .

Note: Dowels (19) are used to locate ring gear (14) .

12. Locate the position of the ring gear in relation to the axle housing. Align the holes in order to install the dowels. Put alignment marks on the ring gear and on the axle housing in order to ensure correct installation.

13. Lower the temperature of ring gear (14) to -70 °C (-94 °F). Install ring gear (14) in the axle housing. The chamfered side of the ring gear should face downward.

    Note: As the ring gear is pressed into the axle housing, tap dowels (19) into the ring gear. After installation, check for full seating of ring gear (14) against the housing shoulder. The dowels must be flush with the ring gear.

14. Install dowels (19) . Peen the housing near the dowels in order to retain the dowels.

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Illustration 4	g00733633

15. Install Tooling (A) on the axle housing, as shown. Attach a hoist and suitable lifting slings to Tooling (A) . Lower the axle housing onto the axle shaft.

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Illustration 5	g00311444

16. Heat bearing cone (20) to a maximum temperature of 135 °C (275 °F).

17. Install bearing cone (20) on the axle shaft so that there is slight end play. Apply clean SAE 30 oil to the bearing cone, when the bearing cone (20) is cool.

    Note: The adjusting nut must be installed so that the part number is facing away from bearing cone (20) .

18. Apply clean SAE 30 oil on bearing nut (12) . Install bearing nut (12) on the axle shaft. Tighten the nut until a small amount of end play remains.

Note: The seal drag torque is the torque that is needed to rotate the axle housing.

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Illustration 6	g00733847

19. To measure the seal drag torque, install Tooling (G) on the axle housing. Place a torque wrench on the bolt at the center of the bar, as shown. Use the torque wrench to rotate the housing. Record the reading on the torque wrench.

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Illustration 7	g00733851

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Illustration 8	g00733847

20. Rotate the axle housing. Use Tooling (D) to tighten bearing nut (11) . Install Tooling (G) on the axle housing. Place a torque wrench on the bolt at the center of Tooling (G) . The torque wrench reading is equal to the seal drag torque plus the axle bearing preload rolling torque. Use the seal drag torque that was recorded in Step 19.

    Note: The preload rolling torque for new bearings is 4 N·m (3 lb ft) to 9 N·m (6 lb ft). The preload rolling torque for used bearings is 4.5 N·m (3 lb ft) to 3 N·m (2 lb ft).

21. Make sure that axle shaft (6) has zero end play.

22. If the axle bearing preload rolling torque exceeds the specification, back off nut (11) by 1/8 turn and reseat bearing cone (20) against nut (11) . Perform Step 19 again.

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Illustration 9	g00303170

23. The following steps are for the assembly of planetary carrier assembly (5) :

    1. Install retaining ring (3) in the carrier.

    2. Apply a thin coat of clean SAE 30 oil in parts of planetary carrier assembly (5) .

    3. Install bearing (9) in planetary gear (10) .

    4. Install thrust washers (11) and planetary gear (10) in the carrier.

    5. Install shaft (6) in the carrier. Make sure that the spring pin hole in the shaft is aligned with the spring pin hole in the carrier. Install new spring pin (6) through the carrier and in shaft (7) . Install spring pin (6) slightly below the outside surface of the carrier.

    6. Repeat Step 23.a through Step 23.e for the remaining two planetary gears.

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Illustration 10	g00733844

24. Install Tooling (C) and suitable lifting slings to planetary carrier assembly (5) .

25. Use a hoist to install the planetary carrier assembly (5) in the axle housing assembly. The weight of the planetary carrier assembly is 80 kg (176 lb).

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Illustration 11	g00733834

26. Use Tooling (F) to install retaining ring (3) on axle shaft (6) .

27. Remove axle housing assembly (2) from Tooling (F) . Install the bottom half of the axle on Tooling (B) in a vertical position.

28. Apply 6V-6640 Sealant on the mating surfaces of the axle housing and of the differential housing.

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Illustration 12	g00733832

29. Fasten Tooling (A) and a hoist to the rim of the axle shaft. Carefully install the axle housing assembly. The weight of the axle housing assembly (2) is 295 kg (650 lb).

30. Install bolts (1) that secure axle housing assembly (2) to the differential housing. The torque for bolts (1) is 300 ± 40 N·m (220 ± 30 lb ft).

End By:

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