784C and 785C Off-Highway Truck Power Train Caterpillar

Installation Procedure

Note: The following installation procedure should be done with the spindle and wheel assembly in the vertical position in order to adjust the bearings.

Note: Newer machines do not use retaining pins with the wheel bearings therefore steps pertaining to retaining rings may be omitted.

Note: Cleanliness is an important factor. Before installation, clean all parts thoroughly 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.

1. Check all of the O-ring seals, spacers, and the components for wear or damage. Replace the components, if necessary.

Note: The following illustrations are typical examples. The following illustrations may not show the proper orientation for assembly of the components in a vertical position.

2. Lubricate all of the O-ring seals lightly with the lubricant that is being sealed.

Note: For additional information on Duo-Cone seals, refer to Disassembly and Assembly, "Duo-Cone Seals - Install" for the proper handling and installation procedures.

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Illustration 1	g00563073

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Illustration 2	g00563054

3. Install O-ring seal (14) onto seal retainer (12) .

4. Use Tooling (D) in order to install one half of Duo-Cone seal (13) onto seal retainer (12) , as shown.

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Illustration 3	g00563072

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Illustration 4	g00563030

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Illustration 5	g01073294

5. Use Tooling (E) in order to install one half of Duo-Cone seal (7) onto the rear service and parking brake, as shown.

6. Use Tooling (D) (not shown) in order to install the remaining half of Duo-Cone seal (13) onto the service and parking brake (4) , as shown.

7. Install seal retainer (12) onto spindle assembly (9) , as shown.

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Illustration 6	g01073291

8. Use a straight edge and a permanent marker to place a mark (2) through the center of the slots (3) for the retaining pin. Place another mark on the end of the splines on the spindle assembly. These marks are for the installation of the wheel bearings.

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Illustration 7	g00558380

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Illustration 8	g00563025

9. Insert retaining pin (10) into spindle assembly (9) .

10. Attach Tooling (C) to a suitable lifting device. Use Tooling (C) to install special cone (11) onto spindle assembly (9) . The weight of special cone (11) is approximately 59 kg (130 lb).

    Note: Align the slot on special cone (11) with retaining pin (10) .

11. Remove Tooling (C) from the lifting device.

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Illustration 9	g00563070

12. If necessary, lower the temperature of special cup (8) to a temperature of -45 °C (-49 °F).

13. Install special cup (8) onto rear wheel (1) , as shown.

    Note: Be certain that special cup (8) is properly seated in the bore of rear wheel (1) .

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Illustration 10	g00563067

14. If necessary, lower the temperature of special cup (8) to a temperature of -45 °C (-49 °F).

15. Install special cup (8) onto rear wheel (1) , as shown.

    Note: Be certain that special cup (8) is properly seated in the bore of rear wheel (1) .

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Illustration 11	g00563066

16. Use Tooling (E) in order to install the remaining half of Duo-Cone seal (7) onto rear wheel (1) , as shown.

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Illustration 12	g00563024

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Illustration 13	g00563003

17. Insert retaining pin (10) into spindle assembly.

18. Install Tooling (A) onto rear wheel (1) . Attach Tooling (A) to a suitable lifting device in order to position rear wheel (1 ) onto spindle (9) . The weight of rear wheel (1) is approximately 1097 kg (2418 lb).

    Note: Leave rear wheel (1) attached to the suitable lifting device until the retainer is installed.

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Illustration 14	g00563020

19. Use a suitable lift truck in order to install special cone (6) . The weight of special cone (6) is approximately 59 kg (130 lb).

    Note: Align the slot on special cone (6) with retaining pin (10) .

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Illustration 15	g00563014

20. Attach Tooling (B) to a suitable lifting device. Use two 0S-1585 Bolts in order to install Tooling (B) to hub (5) , as shown.

21. Use Tooling (B) in order to install hub (5) , as shown. The weight of hub (5) is approximately 78.3 kg (172.6 lb).

22. Remove two 0S-1585 Bolts in order to remove Tooling (B) from hub (5) . Remove Tooling (B) from the suitable lifting device.

Wheel Bearing Adjustment Procedure

Illustration 16	g00659584
Cross section view of a wheel group assembly. (A) Tapped hole (1) Cup (2) Cone (3) Shim Pack (4) Retainer (5) Bolt (6) Washer

Illustration 17	g00659589
Area (C) The gap is determined by the dimension (C) minus the dimension (B) .

Illustration 18	g00675312
View (B-B) Sequence for the initial tightening procedure (D) Bolt (E) Bolt (F) Bolt (G) Bolt (H) Bolt (4) Retainer

Use the following procedure to adjust the wheel bearings.

1. Clean the tapped holes (A) in the end of the spindle in order to receive the bolts for the retainer (4) .

2. Use an outside micrometer to measure the thickness of the retainer (4) . Measure the thickness near the bolt holes in three different locations. Average the three dimensions and record the average as dimension (B) . Refer to Illustration 17.

3. Ensure that the following parts are installed correctly: Cup (1) , Cone (2) and reaction hub. Use five NEW bolts (5) in order to install the retainer (4) on the spindle. Install five NEW bolts into holes that are equally spaced. Refer to Illustration 16 and Illustration 18.

4. Release the brakes.

   Note: The oil pressure that is required to release the brakes is approximately 4685 ± 200 kPa (680 ± 29 psi).

5. Tighten the five NEW bolts (5) in a clockwise bolt tightening sequence: (D) , (E) , (F) , (G) and (H) . Refer to Illustration 18. Tighten the bolts to a torque of 80 N·m (59 lb ft). Rotate the wheel by two complete revolutions.

6. Repeat Step 5 two more times.

7. Use a depth micrometer to measure the distance between the outside face of the retainer and the end of the spindle. Measure the distance through the two holes which are directly opposite each other. Average the two dimensions and record the average as dimension (C) .

   Note: In addition to the hole pattern in the retainer plate, there are two holes in the retainer plate. The holes can be used to measure dimension (C) .

   Note: If the two measurements differ by more than 0.13 mm (0.005 inch), restart the adjustment procedure at Step 3. Disassemble the wheel assembly and check for any interferences that would prevent the wheel bearings from seating correctly.

8. Calculate the average gap that is between the end of the spindle and the inside face of the retainer. Calculate the average by subtracting dimension (B) from dimension (C) . Record the calculation as dimension (X) and remove the retainer (4) .

9. Calculate the thickness of the shim pack (3) . Add 0.508 mm (0.0200 inch) to the calculated dimension (X) .

10. Install the correct thickness of shim pack (3) , that was calculated in Step 9, between the end of the spindle and the retainer.

    Note: Caterpillar does NOT recommend installing the screen assembly.

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NOTICE
After the bolts have been torque turned once, DO NOT RE-USE the bolts.

11. Use the following items to install the retainer (4) : five NEW bolts (5) , five bolts (5) that were used in Step 5 and ten washers (6) . Tighten the bolts in a cross pattern to a torque of 250 ± 25 N·m (184 ± 18 lb ft).

12. Repeat Step 11 until there is no movement in the bolts.

13. When the proper torque has been reached, tighten the bolts in a cross pattern to an additional 60 ± 5 degrees.

    Note: Decrease the temperature of the final drive oil by removing the screen assembly and increasing the diameter of the retainer holes. Decreasing the temperature of the final drive oil will increase the life of the wheel bearing. Refer to Service Magazine, SEPD045325 January 1999, "Wheel Station Modifications May Decrease Oil Temperatures on Certain Off-Highway Trucks" for the rework procedure.

End By: Install the final drive. Refer to Disassembly and Assembly, "Final Drive - Install".