Inspection Procedure for the Ball Stud for Certain Off-Highway Trucks and Quarry Trucks {4303, 4305} Caterpillar

Off-Highway Truck/Tractor

770 (S/N: BZZ1-UP)

770G (S/N: KD21-UP; RMA1-UP; TWA1-UP; RMD1-UP; KDH1-UP; ECM1-UP; ECX1-UP)

772 (S/N: RLB1-UP; 11S1-UP)

772B (S/N: 64W1-UP)

772G (S/N: KE31-UP; TWB1-UP; RME1-UP; RMH1-UP; LTS1-UP; KEX1-UP; LTX1-UP)

773 (S/N: 63G1-UP)

773B (S/N: 63W1-UP)

773D (S/N: NBJ1-UP; 7ER1-UP; 7CS1-UP)

773E (S/N: BDA1-UP; KEG1-UP; ASK1-UP)

773F (S/N: EED1-UP; EXD1-UP)

776 (S/N: 14H1-UP)

776B (S/N: 6JC1-UP)

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

776D (S/N: 5ER1-UP; AFS1-UP)

777 (S/N: 84A1-UP)

777B (S/N: 4YC1-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)

777G (S/N: GT71-UP; T5A1-UP; TNM1-UP; RDR1-UP; T4Y1-UP)

784B (S/N: 5RK1-UP)

784C (S/N: 2PZ1-UP)

785 (S/N: 8GB1-UP)

785B (S/N: 6HK1-UP)

785C (S/N: 1HW1-UP; APX1-UP; 5AZ1-UP)

785D (S/N: MSY1-UP)

789 (S/N: 9ZC1-UP)

789B (S/N: 7EK1-UP)

789C (S/N: 2BW1-UP)

789D (S/N: SPD1-UP; SHH1-UP)

793 (S/N: 3SJ1-UP)

793B (S/N: 1HL1-UP)

793C (S/N: CBR1-UP; 4AR1-UP; ATY1-UP; 4GZ1-UP)

793D (S/N: FDB1-UP)

793F (S/N: SND1-UP; SSP1-UP; RBT1-UP)

795F AC (S/N: ERM1-UP)

795FAC XQ (S/N: SNT1-UP)

797 (S/N: 5YW1-UP)

797B (S/N: JSM1-UP)

797F (S/N: LAJ1-UP; WSP1-UP)

Quarry Truck

773G (S/N: MWH1-UP; JWS1-UP; T5S1-UP; T5T1-UP)

775B (S/N: 7XJ1-UP)

775D (S/N: 6KR1-UP; 8AS1-UP)

775E (S/N: BEC1-UP)

775F (S/N: EYG1-UP; DLS1-UP)

775G (S/N: T5F1-UP; RFM1-UP; MJS1-UP; T5W1-UP)

Introduction

The inspection procedure of the ball stud uses a straight beam examination. The inspection procedure does not require the ball studs to be removed from the machine. The inspection procedure is used to identify any damage that has developed during the operation of the machine. The recommended interval for this procedure is every 1000 service hours unless an inspection interval has been established for your particular application. The ball studs can develop cracks that may cause the ball stud to fail, and lead to the loss of steering. The inspection procedure references ASTM E114-95 and ASTM E1901-97.

Critical Dimensions

Illustration 1	g01623256
8X-9619 Ball Stud 8X-9620 Ball Stud 156-8136 Ball Stud 192-5702 Ball Stud 438-1135 Ball Stud 338-5050 Ball Stud

Illustration 2	g01623285
273-0120 Ball Stud

Calibration

The calibration must be done with a ball stud that is known to be free of defects.

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Illustration 3	g01424901
Typical example

1. Remove any debris from the flat portion of the threaded end of the ball stud. If necessary, lightly grind the surface in order to remove any rust or scale.

2. Apply 9U-7981 Couplant to the flat portion of the threaded end of the ball stud in order to ensure proper contact with the transducer.
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   Illustration 4	g01424981
   Typical example (4) Transducer (5) Flat portion of the ball stud

3. Place transducer (4) on flat portion (5) of the threaded end of the ball stud.

4. Adjust the range so the back shine from the end of the ball stud on the display screen is set to nine.

   Note: Drilled holes will reflect a signal.

5. Increase the decibel level so the back shine from the end of the ball stud is set to 80 percent full screen height (FSH).

Inspection

Note: The inspection procedure can be performed without the removal of the ball stud.

1. Park the machine on a level surface and stop the engine. Engage the parking brake and chock the wheels.

2. Before inspection, ensure that the "Calibration" procedure has been performed.

3. Set the gate at 20 percent full screen height. Start the gate at the second vertical division and end the gate slightly before the end of the ball stud (eight on the display screen).

4. Remove any debris from the flat portion of the threaded end of the ball stud. If necessary, lightly grind the surface in order to remove any rust or scale.

5. Apply 9U-7981 Couplant to the flat portion of the threaded end of the ball stud in order to ensure proper contact with the transducer.
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   Illustration 5	g01416269
   273-0120 Ball Stud and 338-5050 Ball Stud

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   Illustration 6	g01424995
   8X-9619 Ball Stud 8X-9620 Ball Stud 156-8136 Ball Stud 192-5702 Ball Stud 438-1135 Ball Stud

6. Place the transducer near the center of the flat portion of the threaded end of the ball stud.
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   Illustration 7	g01438008
   Transducer pattern for the flat surface on the threaded end of the ball stud

7. Move the transducer from the center to the outer edge of the flat surface and back to the center of the flat surface. Continue to move the transducer from the center to the outer edge until the entire flat surface area has been covered. Refer to the pattern in illustration 7. Maintain contact between the transducer and the ball stud in order to sustain the proper back wall signal.
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   Illustration 8	g01416467
   273-0120 Ball Stud (D) Area of concern (E) End of ball stud

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   Illustration 9	g01623298
   8X-9619 Ball Stud 8X-9620 Ball Stud 156-8136 Ball Stud 192-5702 Ball Stud 438-1135 Ball Stud (F) Area of concern (G) Bottom of drilled holes (H) End of ball stud

8. Identify the ball stud as an acceptable ball stud or as a damaged ball stud.

Documentation

When the inspection of the ball stud has been completed, document the following information:

• Date of inspection

• Serial number of the inspected machine

• Part number of the inspected ball studs

• Number of inspected ball studs

• Number of ball studs that were damaged per machine

• Initial of operator that performed the inspection

• Any corrective action that was taken

Rejection Criteria

A defect that is indicated in the area of concern on the display screen indicates a damaged ball stud. A complete loss of the reflected signal may also indicate a damaged ball stud.

If no clear defects are found, the machine may be returned to service.

If defects are found on the 273-0120 Ball Stud and 338-5050 Ball Stud, replace the ball stud. Refer to the Disassembly and Assembly Manual for instructions on replacing the ball stud.

If defects are found on the following ball studs, verify the results by a dry magnetic particle examination:

• 8X-9619 Ball Stud

• 8X-9620 Ball Stud

• 156-8136 Ball Stud

• 192-5702 Ball Stud

• 438-1135 Ball Stud

Dry Magnetic Particle Examination

Note: The Dry Magnetic Particle Examination can be completed to verify an ultrasonic indication (defect).

Note: If the dry magnetic particle examination indicates that the ball stud is free of defects, the ball stud may be returned to service. However, if the ball stud has less than 50 percent service life remaining, the ball stud should be replaced.

The ball stud must be removed from the machine to perform the dry magnetic particle examination.

Tooling for the dry magnetic particle examination method requires a DC magnetic yoke, magnetic particle powder, and cleaner. The ball stud must be clean and dry to use this method.

To complete the dry magnetic particle examination, perform the following steps:

1. Thoroughly clean the ball stud. Remove any residual oil or contaminants from the ball stud. Make sure that the ball stud is dry after cleaning.

2. Place the magnetic yoke on the surface at a right angle (90 degrees) to the suspected defect area.

3. Energize the magnetic yoke and apply the magnetic particle powder to the surface of the ball stud between the legs of the yoke.
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   Illustration 10	g01421408
   (6) Magnetic yoke (7) Typical example of a defect in a ball stud that has been identified by a dry magnetic particle examination

4. Check the surface of the ball stud. A crack will appear as a line of magnetic particles. A sharp, irregular, narrow cluster of particles indicates a defect (crack) on the surface. A less defined line or a pattern indicates a defect beneath the surface.

   Note: Particles will accumulate on an area that has a rough surface.

5. If the ball stud has less than 50 percent service life remaining, replace the ball stud. Refer to the Disassembly and Assembly Manual for instructions on replacing the ball stud.