797 Off-Highway Truck Caterpillar

Installation Procedure

1. Remove all paint, dirt, and grease from the mounting areas on the frame and the front suspension group.
   Show/hide table

   Illustration 1	g03881273

2. Install key (15).
   Show/hide table

   Illustration 2	g02139365

   Show/hide table

   Illustration 3	g06014748

3. Use Tooling (A) to install front wheel, brake, and suspension cylinder (8). The weight of front wheel, brake, and suspension cylinder (8) is approximately 8000 kg (17637 lb).

4. Install new bolts (12), new bolts (13), and new studs (14) onto both sides of the suspension cylinder.
   Show/hide table

   Illustration 4	g03881546

   Note: Ensure that the jack bolts are flush or recessed with the bottom of the nut body prior to installation.

5. Apply Tooling (D) to the washer faces under the nut and to the threads of the bolts or studs.

6. Install special nut assemblies (9), (10), and (11) onto both sides of the suspension cylinder.
   Show/hide table

   Illustration 5	g03748862
   View of the nut assembly being installed

7. Spin on special nut assemblies (9), (10), and (11) by hand until seated against the washer.
   Show/hide table

   Illustration 6	g03748894
   View of the small gap between the nut and washer

8. Back off special nut assemblies (9), (10), and (11) by half a turn to provide a gap between the nut body and the washer.
   Show/hide table

   Illustration 7	g03881566
   View A-A

   Show/hide table

   Illustration 8	g03749048

9. Ensure that any excess stud length protrudes through the special nut in the following locations:

   • H

   • J

   • K

   • U

   • V

   • W

   Refer to Illustration 7.

   Show/hide table

   Illustration 9	g03881657
   View of the orientation of the nut assemblies

   Show/hide table

   Illustration 10	g03881656
   View of the orientation of the nut assemblies

10. Use Tooling (B) to perform the following tightening sequence.

    1. Start at the top of the lower flange and torque the four jack bolts that are located at 12:00, 6:00, 2:40 and 8:40 to 38 N·m (28 lb ft) in locations E-K and R-W.

    2. Move to the upper flange and torque the four jack bolts that are located at 12:00, 6:00, 3:00 and 9:00 to 34 N·m (25 lb ft) in locations A-D and L-P.

    3. Move to the lower flange and torque the four jack bolts that are located at 12:00, 6:00, 2:40 and 8:40 to 76 N·m (56 lb ft) in locations E-K and R-W.

    4. Move to the upper flange and torque the four jack bolts that are located at 12:00, 6:00, 3:00 and 9:00 to 68 N·m (50 lb ft) in locations A-D and L-P.

    5. Move to the lower flange and torque all jack bolts in a circular pattern to 76 N·m (56 lb ft) in locations E-K and R-W.

    6. Move to the upper flange and torque all jack bolts in a circular pattern to 68 N·m (50 lb ft) in locations A-D and L-P.

    7. Repeat Step 10e and Step 10f until all jack bolts rotate less than 10 degrees.

       Note: If using air tools, switch to a torque wrench for the final pass.

    8. Set torque wrench to 68 N·m (50 lb ft) and torque all jack bolts in a circular pattern in locations A-D and L-P.

    9. Set torque wrench to 76 N·m (56 lb ft) and torque all jack bolts in a circular pattern in locations E-K and R-W.

    10. Set torque wrench to 95 N·m (70 lb ft) and torque all jack bolts in a circular pattern in locations H-K and U-W.

    11. Check and confirm the torque values at 500 and 1000 machine hours.
    Show/hide table

    Illustration 11	g03835659

11. Use a suitable lifting device to position steering arm (7). The weight of steering arm (7) is approximately 696 kg (1534 lb). Install bolts (7A). Use Tooling (C) to tighten bolts (7A) to a torque of 2800 ± 350 N·m (2065 ± 258 lb ft).
    Show/hide table

    Illustration 12	g03880957

12. Install harness assembly (6) and the connecting hardware.
    Show/hide table

    Illustration 13	g03880948

13. If necessary, remove the grease fitting and reinstall the adapter. Connect grease hose assembly (5) to the adapter.
    Show/hide table

    Illustration 14	g02139263

14. Connect hose assembly (4).
    Show/hide table

    Illustration 15	g02139258

15. Connect hose assemblies (3) and hose assemblies (2). Install clips (1).

16. Repeat Step 1 through Step 15 for the opposite side of the machine.

17. Fill the service and parking brake with oil. Refer to Operation and Maintenance Manual, "Capacities - Refill".
    Show/hide table

    Personal injury or death can result from air in the oil for the brake hydraulic system. Air in the system can prevent complete brake application and it is possible that the wheels on the machine can not be stopped. Air must not be in the oil for the brake hydraulic system to function properly.

18. Remove the air from the service and parking brakes. Refer to Testing and Adjusting, "Brake System Air - Purge".

19. Fill the front wheel with oil. Refer to Operation and Maintenance Manual, "Front Wheel Oil - Change".

20. Fill the hydraulic tank with oil. Refer to Operation and Maintenance Manual, "Capacities - Refill".
    Show/hide table

    Read all Warning labels on the suspension cylinders before servicing. The machine must be on level ground before releasing the nitrogen pressure. Do not check the oil in the suspension cylinder until all of the nitrogen pressure has been released. Do not remove valves, covers, or plugs from the cylinder unless the rod is fully retracted and all of the nitrogen pressure as been released. Stand clear of the machine during suspension cylinder charging, discharging, or testing and adjusting procedures, or while lifting or lowering the machine. Sudden movement upward or downward can cause clearance to change rapidly. Failure to heed this Warning could lead to injury or death.

21. Charge the suspension cylinder with oil and nitrogen. Refer to Special Instruction, SEHS9411, "Servicing the Suspension Cylinders for Off-Highway Trucks".

End By:

1. Install the front tire and rim.