844K Wheel Dozer and 990K Wheel Loader Power Train Caterpillar

Assembly Procedure

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Illustration 1	g06007802

1. Install O-ring seal (23) and speed sensor (24).
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   Illustration 2	g06007985

2. Place the transfer case in a horizontal position.

3. Lower the temperature of bearing cup (22). Install bearing cup (22) in the transfer case.

   Note: The bearing cups must be seated properly in the transfer case.

4. Install tube (20) and dowel (21).
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   Illustration 3	g06007970

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   Illustration 4	g06007928

5. Raise the temperature of bearing cones (19) to a maximum temperature of 135 °C (275 °F). Install the bearing cones (19) on output gear assembly (18).

   Note: The bearing cones must be seated properly on the gear.

6. Install output gear assembly (18) and shim pack (17).
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   Illustration 5	g06007922

7. Lower the temperature of bearing cup (16) and install bearing cup (16) in the output bearing cage. The bearing cup (16) must be seated properly in the output bearing cage.

8. The following steps are used to set the bearing end play for the lower transfer gear.
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   Illustration 6	g06007915

   1. Install O-ring seal (25). With the axis of the output gear in a vertical position, install output bearing cage (15) in the transfer case assembly. Make sure that the bearing cage does not bind in the transfer case assembly.

   2. Install bolts (14). Rotate the gear for a minimum of three revolutions or rotate the gear until the rolling resistance of the gear diminishes to a steady level.
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      Illustration 7	g06008332
      Typical example

   3. Mount Tooling (A) on the input transfer gear housing, as shown in Illustration 7. Measure the end play of the gear assembly by lifting on the gear assembly.

      Note: The desired end play for the gear is 0.152 mm (.0060 inch). The maximum end play for the gear is 0.203 mm (.0080 inch). The end play of the gear must be measured with a dial indicator to determine the correct gear end play.

   4. If the end play is not within the correct range, perform Step 8.a through 8.c again. Add or remove shims to achieve the correct end play.
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   Illustration 8	g06007908

9. Turn over the transfer case assembly.

10. Lower the temperature of bearing cup (12) and install bearing cup (12). Use the appropriate equipment to handle the bearing cup. Bearing cup (12) must be seated properly in the transfer case assembly.

11. Install shim pack (13).
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    Illustration 9	g06007853

12. Raise the temperature of bearing cones (11) to a maximum temperature of 135 °C (275°F). Install bearing cones (11). Bearing cones (11) must be seated properly on the gear.
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    Illustration 10	g06007845

13. Install input gear assembly (10).
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    Illustration 11	g06007838

14. Lubricate lip seal (9) lightly with the Tooling (B).

15. Install lip seal (9) into input bearing cage (6). Install the seal so that the lip is facing toward the outside of the input bearing cage. Install the lip seal until the seal contact with the counterbore in the bearing cage.
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    Illustration 12	g06007825

16. Lower the temperature of bearing cup (8) and install bearing cup (8). Use the appropriate equipment to handle bearing cup (8). Bearing cup (8) must be seated properly in the input bearing cage.

    Note: Lubricate the bore lightly with the lubricant that is being sealed.

17. Install O-ring seal (7).
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    Illustration 13	g06007813

18. With the axis of the input gear in a vertical position, install input bearing cage (6) in the transfer case assembly. Make sure that bearing cage (6) does not bind in the transfer case assembly.

19. Install bolts (5).

20. Rotate the shaft during which tapping the shaft lightly with a mallet, for a minimum of three revolutions or until the rolling resistance of the gear diminishes to a steady level.
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    Illustration 14	g06008342
    Typical example

21. Attach Tooling (A) on the transfer case assembly, as shown in Illustration 14.

22. Measure the end play of the gear assembly by lifting on the gear assembly.

    Note: The desired end play for the gear is 0.152 mm (.0060 inch). The maximum end play for the gear is 0.203 mm (.0080 inch). The end play of the gear must be measured with a dial indicator to determine the correct gear end play.

23. If the end play is not within the correct range, repeat Step18 through 22 . Add or remove shims to achieve the correct end play.
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    Illustration 15	g06007812

    Note: Lubricate the bore lightly with the lubricant that is being sealed.

24. Install O-ring seal (4) and O-ring seal (3) to manifold (2).
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    Illustration 16	g06007810

25. Install manifold (2) and bolts (1).

End by:

a. Install the yoke assembly.

b. Connect the transfer gears to the transmission