2009/03/30 Caterpillar

Off-Highway Truck/Tractor:

776C (S/N: 2TK1-UP)

776D (S/N: 5ER1-UP)

776D (S/N: AFS1-UP)

777C (S/N: 4XJ1-UP)

777D (S/N: AGC1-UP; FKR1-UP; 3PR1-UP; 2YW1-UP; AGY1-UP)

777F (S/N: JRP1-UP; JXP1-UP)

Service Magazine SEPD0985, 30 March 2009, "The Installation of the Shim Pack is Updated for the Front Wheel Bearing". Disregard this article. See the replacement article that follows.

Description of Change: Use the updated setting of the shim pack for the correct preload for the front wheel bearing.

Adaptable To: The new shim thickness is adaptable to the following machines:

• 3PR1-UP

• 2YW1-UP

• AGC1192-UP

• JRP1-1458

The new shim thickness is effective with the following machines:

• JRP1459-UP

Illustration 1	g01255752
(1) Axle (2) Wheel (3) Retainer (4) Threaded holes in retainer (5) Bolts (6) Shim pack (7) Bearing assembly (8) Bearing assembly

Note: Before you proceed, tap the thread holes by hand or use a wire brush on the thread holes. This will remove the thread lock compound.

1. Install wheel (2) and bearing assemblies (7) and (8) onto axle (1) .

2. Without using shim pack (6), use four bolts (5) to assemble retainer (3) to axle (1). Be sure that bolts (5) are equally spaced.

3. If the machine is equipped with oil cooled brakes, torque four bolts (5) to 200 N·m (148 lb ft).

   If the machine is equipped with standard disc brakes, torque four bolts (5) to 140 N·m (103 lb ft).

4. Rotate the wheel for two revolutions in order to seat the bearings.

5. If the machine is equipped with oil cooled brakes, torque four bolts (5) to 200 N·m (148 lb ft).

   If the machine is equipped with standard disc brakes, torque four bolts (5) to 140 N·m (103 lb ft).

6. Completely loosen the four bolts (5) in order to remove the torque.

7. Rotate the wheel for two revolutions.

8. Torque four bolts (5) to 110 N·m (81 lb ft).

9. Rotate the wheel for two revolutions in order to seat the bearings.

10. Torque four bolts (5) to 110 N·m (81 lb ft).

11. Rotate the wheel for two revolutions in order to seat the bearings.

12. Repeat Step 10 and Step 11 until the specified torque does not cause any movement of bolts (5) .

13. Use a depth micrometer to measure the distance from the end of axle (1) to the outer face of retainer (3). Use the two threaded holes (4) in retainer (3) for this measurement. Record the average of the measurements.

    Note: If the difference in the measurements at the two holes is more than 0.13 mm (0.005 inch), do not continue with the wheel bearing adjustment procedure. Remove components from axle (1). Check the axle and bearing assemblies for any interference that would prevent the correct seating of the wheel bearings. Repeat the steps until the measurements are within specifications.

14. Remove retainer (3). Measure the thickness of retainer (3) at the two threaded holes that were used to get the previous measurements. Record the average of the measurements.

15. Use the average distance from the end of axle (1) to the outer face of retainer (3). Subtract the average thickness of retainer (3) from this measurement. This is the distance from the end of axle (1) to the inner face of retainer (3) .

16. Install shim pack (6). In order to determine the shim pack thickness, add 0.488 + 0.000 - 0.050 mm (0.0192 + 0.0000 - 0.0020 inch) to the distance from Step 15.

    Note: If a 200-4529 Bearing Preload Adjuster Gp tool is used, then the tool requires no modifications. No rework or adjustments are required in order to achieve the new preload setting. Calibrate the tool annually. Refer to the operations manual in order to properly calibrate the tool.

    Note: Apply 9S-3263 Thread Lock to bolts (5) before final assembly.

17. Install 8 bolts (5). While you rotate the wheel, torque bolts (5) to 250 ± 14 N·m (184 ± 10 lb ft).