Procedure to Inspect and Repair the Front Wheels on 785 - 797 Off-Highway Truck {0599, 0700, 0730, 0731, 4006, 4200, 4209, 4251} Caterpillar

Mining Truck

794 AC (S/N: HRT1-UP)

Off-Highway Truck/Tractor

785 (S/N: 8GB1-UP)

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

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

785D (S/N: DMC1-UP; 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)

794 AC (S/N: MN51-UP; MT51-UP)

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

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

797B (S/N: JSM1-UP)

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

Introduction

Table 1

Revision	Summary of Changes in SEBF9368
07	Revised Illustrations 16, 17,18,19,20, and 21. Added Tables 6,7,8, 910, and 11. Added several part numbers to Table 3. Added 3 sales model 794 AC effectivity, updated part numbers, and boilerplate.
06	Added sales model 785 and 789
05	Reworded oil drain port crack removal procedure.
04	Added 793 Off-Highway Truck serial number prefixes

© 2019 Caterpillar All Rights Reserved. This guideline is for the use of Cat dealers only. Unauthorized use of this document or the proprietary processes therein without permission may be violation of intellectual property law.

Information contained in this document is considered Caterpillar: Confidential Yellow.

This Reuse and Salvage Guideline contains the necessary information to allow a dealer to establish a parts reusability program. Reuse and salvage information enables Caterpillar dealers and customers to benefit from cost reductions. Every effort has been made to provide the most current information that is known to Caterpillar. Continuing improvement and advancement of product design might have caused changes to your product which are not included in this publication. This Reuse and Salvage Guideline must be used with the latest technical information that is available from Caterpillar.

For technical questions when using this document, work with your Dealer Technical Communicator (TC).

To report suspected errors, inaccuracies, or suggestions regarding the document, submit a form for feedback in the Service Information System (SIS web) interface.

Canceled Part Numbers and Replaced Part Numbers

This document may include canceled part numbers and replaced part numbers. Use the Numerical Part Record (NPR) on the Service Information System Website (SIS web) for information about canceled part numbers and replaced part numbers. NPR will provide the current part numbers for replaced parts.

Important Safety Information

Illustration 1	g02139237

Work safely. Most accidents that involve product operation, maintenance, and repair are caused by failure to observe basic safety rules or precautions. An accident can often be avoided by recognizing potentially hazardous situations before an accident occurs. A person must be alert to potential hazards. This person should also have the necessary training, skills, and tools to perform these functions properly. Safety precautions and warnings are provided in this instruction and on the product. If these hazard warnings are not heeded, bodily injury or death could occur to you or to other persons. Caterpillar cannot anticipate every possible circumstance that might involve a potential hazard. Therefore, the warnings in this publication and the warnings that are on the product are not all inclusive. If a tool, a procedure, a work method, or operating technique that is not recommended by Caterpillar is used, ensure that it is safe for you and for other people to use. Ensure that the product will not be damaged or the product will not be made unsafe by the operation, lubrication, maintenance, or the repair procedures that are used.

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Improper operation, lubrication, maintenance or repair of this product can be dangerous and could result in injury or death. Do not operate or perform any lubrication, maintenance or repair on this product, until you have read and understood the operation, lubrication, maintenance and repair information.

Safety precautions and warnings are provided in this manual and on the product. If these hazard warnings are not heeded, bodily injury or death could occur to you or to other persons.

The hazards are identified by the “Safety Alert Symbol” which is followed by a “Signal Word” such as “DANGER”, “WARNING” or “CAUTION”. Refer to Illustration 2 for an example of a “WARNING” Safety Alert Symbol.

Illustration 2	g00008666

This safety alert symbol means:

Pay Attention!

Become Alert!

Your safety is Involved.

The message that appears under the safety alert symbol explains the hazard.

Operations that may cause product damage are identified by "NOTICE" labels on the product and in this publication.

Caterpillar cannot anticipate every possible circumstance that might involve a potential hazard. The safety information in this document and the safety information on the machine are not all inclusive. Determine that the tools, procedures, work methods, and operating techniques are safe. Determine that the operation, lubrication, maintenance, and repair procedures will not damage the machine. Also, determine that the operation, lubrication, maintenance, and repair procedures will not make the machine unsafe.

The information, the specifications, and the illustrations that exist in this guideline are based on information which was available at the time of publication. The specifications, torques, pressures, measurements, adjustments, illustrations, and other items can change at any time. These changes can affect the service that is given to the product. Obtain the complete, most current information before you start any job. Caterpillar dealers can supply the most current information.

Summary

Illustration 3	g06022265
Inner surface view of front wheel (A) Entire Inner Surface

Illustration 4	g06022232
Outer surface view of front wheel. (B) Entire Outer Surface (C) Oil Drain Port Location

This guideline provides instructions for inspection, crack detection, and repair of cracks developing on the front wheels of 785 - 797 Off-Highway Trucks. The cracks can be present on the entire inner (A) and outer surface (B) of the wheel, and also the drain port location (C).

The procedure can be performed with the wheel on or off the machine. Before performing this procedure, inspect the wheel. If any cracks are discovered on the wheel, perform the repair with the wheel on the machine. If the wheel cannot be repaired, remove the wheel from the machine.

This guideline contains the latest standards of engineering, which will help minimize owning and operating costs. A part is expected to reach the next Planned Component Rebuild (PCR) if the part meets the specifications within this guideline and the part is intended for a similar application. Use this guideline to determine whether a part should be reused. Do not install a part that is not reusable. During reconditioning, correct any condition that might have caused the original failure.

The dimensions and tolerances provided are to return a part / component to specification. The dimensional information alone is not solely used to condemn a part from reuse. Follow visual inspections and the "Crack Detection Methods" section for further guidance.

References

Table 2

References
Media Number	Publication Type & Title
Channel1	"Why Reuse and Salvage Parts"
	https://channel1.mediaspace.kaltura.com/media/Why+Reuse+and+Salvage+Parts/0_ae9rhu2z
—	Applicable Operation and Maintenance Manual
REHS5099	Special Instruction "Procedure to Remove Raised Markings in the Wheel Well Area of the Wheels on Certain 797 and 797B Off-Highway Trucks"
SEBF8187	Reuse and Salvage Guidelines "Standardized Parts Marking Procedures"
SEBF8443	Reuse and Salvage Guidelines "Inspection and Repair Procedures for Wheels that are Used on Off-Highway Trucks"
SEBF8728	Reuse and Salvage Guidelines "Specifications for Inspection of Driveline Fasteners"

Service Advisories, Service Letters, and Technical Service Bulletins

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NOTICE
The most recent Service Advisories, Service Letters, and Technical Service Bulletins that are related to this component should be reviewed before beginning work. Often Service Advisories, Service Letters, and Technical Service Bulletins contain upgrades in repair procedures, parts, and safety information which pertain to the components being repaired.

Tooling and Equipment

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NOTICE
Failure to follow the recommended procedure or the specified tooling that is required for the procedure could result in damage to components. To avoid component damage, follow the recommended procedure using the recommended tools.

Note: The Tooling and Equipment in Table 3 is not an all inclusive list of Tooling required to perform every task within this document. Tooling needs may vary for the scope of work to be performed for each specific rebuild.

Table 3

Required Tooling and Equipment
Part Number	Description	Designation
— (1)	Personal Protective Equipment (PPE)	Personal Protection
— (2)	Clevis/ Shackle	Component Repositioning and Movement
— (2)	Lifting Eye Assemblies	Component Repositioning and Movement
— (2)	Tool (Cribbing)	Component Repositioning and Movement
—	Suitable Lifting Device	Component Repositioning and Movement
1U-7262	Telescoping Magnet	General Tooling
1U-9367	Automatic Tape Measure (1-inch X 26- ft) 25.4- mm x 8- m	Measurement Checks
367-9109	Caliper 150 mm (6.00 inch)	Profile Measurement
4S-9405	Caliper 304.8 mm (12.00 inch)	Profile Measurement
5P-3920	Tool Rule 304.8 mm (12.00 inch)	Measurement Checks
385-9422	Tools (Micrometer) Internal (2 - 24 inch)	Internal Measurement Checks
386-3364	Tool (Ruler) 1,000.0 mm (39.37 inch)	Measurement Checks
—	Straight Edge	Flatness/ Straightness Checks
1U-5516	Disc (Coarse)	Surface Preparation / De-burring
1U-5518	Threaded Shaft	Surface Preparation / De-burring
1U-5519	Holder (Disc Pad)	Surface Preparation / De-burring
1U-6791	Wheel (Grinding)	Surface Preparation / De-burring
1U-6794	Wheel (Grinding)	Surface Preparation / De-burring
1U-6832	Disc (Abrasive)	Surface Preparation / De-burring
1U-6846	Disc (Abrasive)	Surface Preparation / De-burring
4C-8514	Wheel (2 x 1 inch) (60 Grit)	Surface Preparation / De-burring
4C-8515	Grinding Wheel (F-Grade) (2 x 1 inch) (120 Grit)	Surface Preparation / De-burring
222-3076	Die Grinder (Right Angle)	Surface Preparation / De-burring
222-3077	Die Grinder	Surface Preparation / De-burring
236-8097	Carbide Bur	Crack Excavation
254-5319	Brush 76.2 x 50.8 mm (3.00 x 2.00 inch)	Surface Preparation / De-burring
9U-7377 (3)	Metal Marking Pen	Parts Marking
223-1154	Engraver Air	Parts Marking
6V-2010	Polishing Stone	Gear Polishing
1U-9918	Brush	General Cleaning
1U-5512	Abrasive Material (Roll)	General Cleaning
8T-7765	Surface Reconditioning Pad (180 Grit)	General Cleaning
162-5791	Towel	General Cleaning
1U-9978	Brush	Paste Application
—	Loctite 680	Bore Sleeving
222-3074	Wheel Grinder Group	Welding Preparation Weld Removal/ Crack Excavation
458-9587 (4)	Paint Yellow	Touch Up
479-5400 (5)	Paint Yellow	Touch Up
8S-2257	Magnifying Glass	Visual Surface Inspection (VT)
9U-6182	Mirror (Telescoping)	Visual Surface Inspection (VT)
9U-7231	Flashing Lights Conversion Kit	Visual Surface Inspection (VT)
4C-9442	Light	Visual Surface Inspection (VT)
— (2)	Bright Incandescent Light	Visual Surface Inspection (VT)
—	Reflective Surface for Inspection	Visual Surface Inspection (VT)
262-8390	Microscope (40-Power) Pocket	Crack/ Measurement Inspection
288-4209	Paper Towel	Liquid Penetrant Testing (PT)
1U-9915	Brush Curved Handle Wire	General Cleaning/ Liquid Penetrant Testing (PT)
—	Developer	Liquid Penetrant Testing (PT)
—	Penetrating Oil	Liquid Penetrant Testing (PT)
—	Solvent Cleaner	General Cleaning/ Liquid Penetrant Testing (PT)
263-7184	Crack Detection Kit (Magnetic Particle)	Dry Magnetic Particle Testing (MPT)
—	Paint Pen	Dry Magnetic Particle Testing (MPT)
459-0184	Lamp Group Ultraviolet	Wet Magnetic Particle Testing (MPT)
505-8671	Fluid Ultrasonic Wear Indicator	Ultrasonic Testing (UT)
415-4055	Tool Group(Ultrasonic)	Ultrasonic Testing (UT)

(1)	Refer to PERJ1017Special Publication, "Dealer Service Tools Catalog" for Personal Protective Equipment (PPE) part numbers suitable by geographic location and local safety standards.
(2)	Refer to Special Publication, PERJ1017, "Dealer Service Tools Catalog" for suitable tooling.
(3)	Available in the United States only.
(4)	Available in North and South America (except Canada).
(5)	Available in Canada, APD, and EAME.

Standardized Parts Marking

Reference: SEBF8187Reuse and Salvage Guidelines, "Standardized Parts Marking Procedures".

The code is a Cat standard and is used to record the history of a component. The code will identify the number of rebuilds and hours at the time of each rebuild. This information is important and should be considered for any decision to reuse a component.

Ensure that the mark is not covered by a mating part.

The procedure for marking components is a Cat standard. This code is helpful when the machine is sold into a different territory after the first rebuild. During an overhaul, the previous code of a part should never be removed.

Example 1

Illustration 5	g03748255
Typical Example

Illustration 5 shows code (1-15). The first number (1) indicates that the component had been rebuilt once. The second number (15) indicates that there were 15,000 hours on the component at the time of rebuild.

Example 2

Illustration 6	g03748362
Typical Example

Illustration 6 shows code (1-12) and code (2-10). Code (2-10) represents the information from the second rebuild. The first number (2) indicates that the component had been rebuilt twice. The second number (10) indicates that 10,000 hours accumulated on the component between the first and second rebuild.

Note: Add the first and second rebuild hours to obtain the total number of hours for the component in Illustration 6. In this example, the component has a total of 22,000 hours.

Prepare the Area for Inspection

Illustration 7	g00008666

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Personal injury can result when using cleaner solvents. To help prevent personal injury, follow the instructions and warnings on the cleaner solvent container before using.

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Personal injury can result from air pressure. Personal injury can result without following proper procedure. When using pressure air, wear a protective face shield and protective clothing. Maximum air pressure at the nozzle must be less than 205 kPa (30 psi) for cleaning purposes.

Illustration 8	g03794147
Typical burr removal Tooling. (A) Die Grinder, Right Angle (B) Wheel Grinder, Group (C) Conditioning Discs, Disc pad Holder, and Threaded Shaft (D) Flapper Wheel

• Clean all surfaces for inspection before you inspect the part. Make sure that you remove all rust, dirt, paint, grease oil, and fluids or moisture

• During cleaning, do not damage machined surfaces.

• Use pressurized air to dry parts.

• Inspect nuts and bolts removed, refer to , SEBF8728, "Specifications for Inspection of Driveline Fasteners" for further information.

Front Wheel Part Numbers

This procedure applies to the following front wheels:

Table 4

Front Wheel Part Numbers and Material
Part Number	Description	Casting
8X-1469	Front Wheel	Steel
8X-2634	Front Wheel	Steel
106-7888	Front Wheel	Steel
125-5938	Front Wheel	Steel
144-0803 570-7050	Wheel	Ductile Iron
265-3191	Front Wheel	Steel
266-3613 380-9084	Wheel	Steel
309-4130 381-6982	Wheel	Steel
309-4132	Wheel	Steel
351-6652 570-7050	Wheel	Ductile Iron
480-5059	Front Wheel	Steel

Front Wheel Inspection Sheet

Action Required:

• Steam clean and visually inspect the front wheel for cracks.

• Use photos to document cracks found or suspected from visual inspection.

• Record all numbers and letters from wheel.

• Give the inspection sheet with all information and photos to the site supervisor.

Illustration 9	g03731422
(1) Country of Origin (2) Serial Number (3) Numerical Code (4) Foundry Emblems

Illustration 10	g03731871
(5) Part number location and engineering change number

Note: Refer to Illustration 9 & 10 for locations.

Note: Markings may have been removed from the wheel. Refer to Special Instruction, REHS5099, "Procedure to Remove Raised Markings in the Wheel Well Area of the Wheels on Certain 797 and 797B Off-Highway Trucks".

Before performing the rework procedure, record the following information for each wheel.

• Truck Serial Number

• Service Hours (truck)

• Service Hours (each wheel if known)

• Part number and Engineering Change Number (each wheel)

• Serial Number (each wheel)

• Numerical Code (each wheel)

Table 5

Data Capture Form
Customer:	Machine:	SMU:	Date:
Wheel:	Part Number	Numerical Code	Casting Serial Number	Comment
Left
Right

Crack Inspection

Refer to applicable Operation and Maintenance Manual (OMM) for the following:

• Front wheels daily inspection.

• Front wheels during the 250-hour check of the magnetic plug.

• Font wheels during the 500-hour engine oil and filter change.

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Illustration 11	g06019000
(A) Visible cracks in the radius.

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Illustration 12	g02828736
Magnified view of area (A), crack measured in millimeters.

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Illustration 13	g02828264
Typical view of surface defect locations.

1. Visually inspect the wheels for cracks on cast surfaces. Salvage procedure must be performed to eliminate cracks or reduce crack size below the minimum allowed. Refer to the "Crack Detection Methods" section.

Inspection Procedure for Dross on 480-5059 Front Wheels

Note: Dross inspection and criteria apply to the wheel on or off the truck.

Illustration 14	g06019028
Example of crack length that meets reuse criteria. (AA) 15.0 mm (0.60 inch) (BB) 20.0 mm (0.80 inch)

Some areas of the ductile iron front wheels may be affected by dross, a surface condition.

Use the following logic in dross affected areas to determine size and course of action.

• Indications may run together randomly.

• Indications may be close to one another or nearly touching.

• Indication length: Total continuous length of the longest single or multiple joined segments producing a linear or non-linear indication by Magnetic Particle Testing (MPT). Refer to the "Crack Detection Methods" section.

• Indication length less than 40.0 mm (1.60 inch) can run as-is.

• Indication lengths greater than 40.0 mm (1.60 inch) must be reduced by removing 6.0 mm (0.24 inch) of material and blending the transition. Refer to Illustration 15 for an example of grinding and blending.

Salvage Procedure with the Front Wheel on the Truck

1. Crack lengths less than 40.0 mm (1.60 inch) do not require service. Crack lengths greater than 40.0 mm (1.60 inch) require Liquid Penetrant Testing (PT) confirmation prior to servicing. Refer to the "Crack Detection Methods" section.

2. Grind the surface of suspect area using 180 grit or finer media to perform Liquid Penetrant Testing (PT).

3. Grind a maximum of 6.0 mm (0.24 inch) deep using a die grinder with a carbide bur to remove the crack or to reduce the crack length to less than 40.0 mm (1.60 inch).
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   Illustration 15	g03722183
   Typical view of surface after grinding and blending

4. If grind of 6.0 mm (0.24 inch) depth is successful, then the surface must be grounded and blended to a smooth surface radius.

   Note: No sharp transitions are allowed.

   Use an infrared thermometer to monitor the temperature of the wheel. The wheel temperature must remain below 220° C (428° F) during the grinding process.

   Note: Refer to the"Ultrasonic Testing (UT)"to determine thickness.

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   Illustration 16	g06412681
   8X-2634 Front Wheel

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   Table 6

   Front Wheel Part Number 8X-2634 Acceptable Dimensions		Record Actual Dimensions
   Location	Minimum	Measurement
   A	50.00 mm (1.969 inch)
   B	33.00 mm (1.300 inch)
   C	39.000 mm (1.540 inch)
   D	50.00 mm (1.969 inch)
   E	100.00 mm (3.940 inch)
   F	150.00 mm (5.910 inch)
   G Radius	R 457.00 mm (17.993 inch)
   H	23.000 mm (0.906 inch)
   J Radius	R 50.00 mm (1.969 inch)

   1. To ensure that the R 457.0 mm (17.99 inch) and R 50.0 mm (1.97 inch) radius has been maintained on 8X-2634 Front Wheel, fabricate a device with a diameter of 914.0 mm (35.98 inch) and 100.0 mm (3.94 inch) as shown in Illustration 16.
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      Illustration 17	g06412899
      Minimum thickness and radius dimensions of 106-7888 Front Wheel. Must maintain a minimum thickness of 29.0 mm (1.14 inch) for distance of (A) and (B). For web areas maintain ratio for thickness between points.

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      Table 7

      Front Wheel Part Number 106-7888 Acceptable Dimensions		Record Actual Dimensions
      Location	Minimum	Measurement
      A	29.00 mm (1.142 inch)
      B	29.00 mm (1.142 inch)
      C	27.00 mm (1.063 inch)
      D	28.00 mm (1.103 inch)
      E	35.00 mm (1.378 inch)
      F	43.00 mm (1.693 inch)
      G	67.00 mm (2.638 inch)
      H	118.00 mm (4.646 inch)
      J Radius	R 80.00 mm (3.150 inch)
      K	29.00 mm (1.142 inch)

   2. To ensure that the R 80.0 mm (3.15 inch) radius has been maintained on 106-7888 Front Wheel, fabricate a device with a diameter of 160.0 mm (6.30 inch) as shown in Illustration 17.
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      Illustration 18	g06412966
      Minimum thickness and radius dimensions of 125-5938 Front Wheel. Must maintain a minimum thickness of 25.0 mm (0.984 inch) for distance of (A) and (B). For web areas maintain ratio for thickness between points.

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      Table 8

      Front Wheel Part Number 125-5938 Acceptable Dimensions		Record Actual Dimensions
      Location	Minimum	Measurement
      A	25.00 mm (0.984 inch)
      B	25.00 mm (0.984 inch)
      C	35.00 mm (1.378 inch)
      D	34.00 mm (1.339 inch)
      E	44.00 mm (1.733 inch)
      F	54.00 mm (2.126 inch)
      G Radius	R 50.00 mm (1.969 inch)
      H	97.00 mm (3.819 inch)
      J	159.00 mm (6.260 inch)
      K Radius	R 80.00 mm (3.150 inch)
      L	25.00 mm (0.984 inch)

   3. To ensure that the R 80.0 mm (3.15 inch) radius has been maintained on 125-5938 Front Wheell, fabricate a device with a diameter of 160.0 mm (6.30 inch) as shown in Illustration 18.
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      Illustration 19	g06412990
      Minimum thickness and radius dimensions of 265-3191 Front Wheel and 309-4132 Wheel Must maintain a minimum thickness of 28.0 mm (1.102 inch) for distance of (A) and (B). For web areas maintain ratio for thickness between points.

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      Table 9

      Front Wheel Part Number 265-3191 and 309-4132 Acceptable Dimensions		Record Actual Dimensions
      Location	Minimum	Measurement
      A	28.00 mm (1.103 inch)
      B	28.00 mm (1.103 inch)
      C	20.00 mm (0.788 inch)
      D	49.00 mm (1.929 inch)
      E	61.00 mm (2.402 inch)
      F	86.00 mm (3.386 inch)
      G Radius	R 30.00 mm (1.181 inch)
      H	70.00 mm (2.7560 inch)
      J	120.00 mm (4.725 inch)
      K	28.00 mm (1.103 inch)
      L Radius	R 195.00 mm (7.677 inch)

   4. To ensure that the R 195.0 mm (7.68 inch) radius has been maintained on 265-3191 Front Wheel and 309-4132 Wheel, fabricate a device with a diameter of 390.0 mm (15.35 inch) as shown in Illustration 19.
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      Illustration 20	g06413066
      Minimum thickness and radius dimensions of 570-7050 Front Wheel. Must maintain a minimum thickness of 35.0 mm (1.38 inch) for distance of (A) and (B). For web areas maintain ratio for thickness between points.

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      Table 10

      Front Wheel Part Number 570-7050 Acceptable Dimensions		Record Actual Dimensions
      Location	Minimum	Measurement
      A	35.00 mm (1.378 inch)
      B	35.00 mm (1.378 inch)
      C	23.00 mm (0.906 inch)
      D	38.00 mm (1.496 inch)
      E	43.00 mm (1.693 inch)
      F	46.00 mm (1.811 inch)
      G Radius	R 70.00 mm (2.756 inch)
      H	67.00 mm (2.638 inch)
      J	107.00 mm (4.213 inch)
      K Radius	R 70.00 mm (2.756 inch)
      L	35.00 mm (1.378 inch)

   5. To ensure that the R 70.0 mm (2.76 inch) radius has been maintained on 570-7050 Wheel, fabricate a device with a diameter of 140.0 mm (5.5 inch) as shown in Illustration 20.
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      Illustration 21	g06413133
      Minimum thickness and radius dimensions of 380-9084 Wheel and 381-6982 Wheel.

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      Table 11

      Wheel Part Number380-9084 and 381-6982 Acceptable Dimensions		Record Actual Dimensions
      Location	Minimum	Measurement
      A	25.00 mm (0.984 inch)
      B	35.00 mm (1.378 inch)
      C	50.00 mm (1.969 inch)
      D	50.00 mm (1.969 inch)
      E Radius	45.00 mm (1.772 inch)
      F	75.00 mm (2.953 inch)
      G	100.00 mm (3.937 inch)
      H Radius	R 75.00 mm (2.953 inch)
      J	42.00 mm (1.654 inch)
      K	22.00 mm (0.866 inch)

   6. To ensure that the R 75.0 mm (3.00 inch) radius has been maintained on 380-9084 Wheel and 381-6982 Wheel, fabricate a device with a diameter of 150.0 mm (6.00 inch) as shown in Illustration 21.
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   Illustration 22	g02828601
   Typical view of poor grinding measured in millimeters

5. When grinding on the wheel, the minimum wall thickness and radius must be maintained in order for the component to be salvaged.

   Note: Illustration 22 shows that the cracks can still be identified after grinding. The ground area is not blended properly with the surface. There are also sharp transitions left around the grind. The repair would not pass inspection.

   Note: No sharp transitions are allowed.

6. If the crack cannot be reduced to 40.0 mm (1.60 inch) or less while maintaining the maximum grind depth of 6.0 mm (0.24 inch), then DO NOT USE AGAIN.

7. Repaint any areas ground during inspection or salvage before returning truck to service.

Oil Drain Port Crack Removal and Rework with Front Wheel on the Truck

1. Perform visual inspection of the drain port spot face. Cracks develop in the small radius in the machined feature.

2. If a crack greater than 16.0 mm (0.63 inch) is discovered or suspected, a secondary Liquid Penetrant Testing (PT) must be used to confirm the presence of a crack. Refer to the "Crack Detection Methods" section.

3. If a crack greater than 16.0 mm (0.63 inch) exists, use a die grinder and carbide bur to remove 2.0 mm (0.079 inch) of material at a time until the crack length is reduced below 16.0 mm (0.63 inch). Maximum grind depth is 6.0 mm (0.24 inch).
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   Illustration 23	g03722236
   View of crack before grinding.

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   Illustration 24	g03722238

4. Contour the transition from the drain port spot face to the wheel as-cast surface with a 6.0 mm (0.24 inch) radius and blend 25.0 mm (0.98 inch) to either side of the removal area. Finish with a 180 grit buffer pad to remove all markings from the rough grind operation.

Ultrasonic Thickness Inspection Procedure with the Wheel on the Truck

Note: Personnel performing the Ultrasonic Testing (UT) must be at least Level I Certified Technician as defined by ASNT-TC-1A. Personnel must be trained by a Level II or Level III technician to perform the procedures and rejection criteria.

The instrument is a pulse echo type thickness gauge. A 2.25 MHz 0.5 in diameter straight beam dual element transducer is used. Couplant must be used to permit the transmission of the acoustic energy from the search unit into the component that is to be inspected.

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Illustration 25	g02846636
Area on backside of front wheel for testing.

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Illustration 26	g02863796
Typical view of test area on back side of front wheel.

1. Clean and remove the paint from the surface of each area to be tested. The surface of each area tested must be free from dirt, rust, loose paint, or any material that could interfere with sound propagation.

2. Measure the thickness of the front wheel at the location in Illustration 25.

   Note: The nominal thickness of the wheel at the location shown in Illustration 25 and Illustration 26 is 40 mm (1.60 inch).

3. Use the Auto Cal function and follow the screen prompts to finish the calibration.

   Note: The material velocity should read approximately 5387 m/s (0.2121 inch./us).

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   Illustration 27	g02829878
   Typical view of couplant in repaired area.

4. Inspect suspect material.

5. Place a small amount of couplant in the area that has been ground for crack removal.

6. Move transducer in a raster pattern to find the lowest thickness. Mark the area and record the minimum thickness on the wheel surface.

7. Measure and inspect the thickness of suspect material. The minimum thickness of the component under inspection must be greater than the dimensions shown in Illustrations18 through 21.

   Note: The minimum radius must be maintained in order for the component to be salvaged.

Ultrasonic Thickness Inspection Procedure with the Front Wheel Removed from the Truck

Do not remove raised lettering and logos. If raised lettering and logos are removed the information must be stamped at a different location on the same surface.

1. Clean the surface of each area to be tested. The surface of each area tested must be free from dirt, rust, loose paint, or any material that could interfere with sound propagation.

2. Perform either a dry or wet magnetic particle process for inspection. Refer to "Crack Inspection" for instructions on dry or wet magnetic particle process.

   Note: Wheels with cracks 20.0 mm (0.80 inch) or shorter as determined by magnetic particle inspection may be reused without reconditioning of the cracked surface.

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   Illustration 28	g03748250
   Typical view caliper measurement of wheel flange thickness

3. Use calipers to measure the outside machined flange. This measurement is the manual thickness measurement. Use the manual thickness measurement to conduct a one point thickness calibration.

4. Use the Auto Cal function and follow the screen prompts to finish the calibration.

   Note: The material velocity should read approximately 5387 m/s (0.2121 inch/us).

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   Illustration 29	g02829878
   Typical view of couplant in repaired area.

5. Inspect suspect material.

6. Place a small amount of couplant in the area that has been ground for crack removal.

7. Move the transducer in a raster pattern to find the lowest thickness. Mark the area and record the minimum thickness on the wheel surface.

8. Measure and inspect the thickness of suspect material. The minimum thickness of the component under inspection must be greater than the dimensions shown in Illustrations 18 through 21.

   Note: The minimum radius must be maintained in order for the component to be salvaged.

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   Illustration 30	g02830258
   Typical view of using large calipers for measurement

9. Large calipers can be used where access of ultrasonic equipment is not possible. The use of calipers is only possible on the outside casting surfaces near the outer flange of the wheel.

10. To remove or reduce the size of cracks longer than 20.0 mm (0.80 inch) the wheels may be ground to a depth that preserves the dimensions shown in Illustration 18 through 21.

11. If grind of 6.0 mm (0.24 inch) depth is successful, then the surface must be grounded and blended to a smooth surface radius.

    Note: No sharp transitions are allowed.

12. If the crack cannot be reduced to 20.0 mm (0.80 inch) or less while maintaining the maximum grind depth of 6.0 mm (0.24 inch), then the wheel must be taken out of service and scrapped.

13. Minimum wall thickness must be maintained (Illustration 18 through 21). If crack removal process violates minimum wall thickness the wheel must be taken out of service and scrapped.

14. Repaint any areas ground during inspection or salvage before returning truck to service.

Inspection and Salvage Procedure for 125-5938 and 265-3191 Front Wheels

Illustration 31	g06019272
View of 125-5938 Front Wheel (A) Surface Inspection (B) 1000.0 mm (39.37 inch)

Illustration 32	g06020326
View of 265-3191 Front Wheel (A) Surface Inspection (B) 1000.0 mm (39.37 inch)

Illustration 33	g06036924
(C) Cover Side (D) Brake Side

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Illustration 34	g06036944
(E) ‘SACL’ (F) ‘DBS’ (E) YEAR of manufacture by last two (2) letters of Numerical Code

1. Confirm that wheel requires surface inspection and identify defective wheels by foundry logo. Refer to Illustration 34 for location and description of logos.

   • Wheels with ‘SACL’ (E) on cover side of wheel must be inspected, proceed to Step 3.

   • Wheels with ‘DBS’ (F) on the brake side of wheel do not have to be inspected.

2. Determine YEAR of manufacture by last two (2) letters of Numerical Code.

   • Numerical Code ends with ‘UR’, ‘UE’, ‘UM’, ‘UU’, ‘UN’ (G), proceed to Step 3.

   • Numerical Code ends with ‘UA’ wheel is OK TO USE AGAIN.

3. Use Magnetic Particle Testing (MPT) to inspect as-cast surface from duo-cone, surface (A), refer to Illustrations 31 and 32. Refer to "Crack Detection Methods" for instructions on dry or wet Magnetic Particle Testing (MPT).

   • No cracks are permitted on surface (A).

   • If cracks found, remove crack by grinding only to 6.0 mm (0.24 inch) maximum depth.

   • If cracks cannot be removed, DO NOT USE WHEEL AGAIN.

4. Using a radius gauge check casting geometry, refer to Illustrations 31 and 32.

   • 125-5938 - R 50.0 mm (1.97 inch)

   • 265-3191 - R 30.0 mm (1.18 inch)

5. Using 80 grit abrasive, grind the wheel surface as required to meet radius per part number in Step 4.

6. Finish all reworked surfaces with 200 grit abrasive to complete upgrade process.

7. Repaint any areas ground during inspection or salvage before returning truck to service.

Oil Drain Port Crack Removal and Rework with Front Wheel Removed from the Truck

Illustration 35	g06023521
(A) Blend to R6.0 mm (0.24 inch) minimum (B) Blend to R10 mm (0.39 inch) minimum (C) Blend to R10 mm (0.39 inch) minimum (D) Blend to R25 mm (0.98 inch) minimum

Note: EXPLORATION GRINDING IS NOT NECESSARY

1. Perform visual inspection of the drain port spot face. Cracks develop in the small radius in the machined feature.

2. If a crack greater than 16.0 mm (0.63 inch) is discovered or suspected, a secondary dye penetrant process must be used to confirm the presence of a crack. Refer to "Crack Detection Methods" for instructions on Liquid Penetrant Testing (PT).
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   NOTICE
   Take care not to remove material on the drain port sealing surface.

3. If a crack greater than 16.0 mm (0.63 inch) exists, use a die grinder and a carbide bur to remove 2.0 mm (0.079 inch) of material at a time until the crack length is reduced below 16.0 mm (0.63 inch). Maximum grind depth is 6.0 mm (0.24 inch)

4. Blend to the proper radius. Refer to Illustration 35.

5. Maintain wall thickness.

Crack Detection Methods

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NOTICE
It is important that the instructions furnished with the detection equipment are followed closely when checking any component, regardless of which crack detection method is used. Failure to do so may cause inaccurate results or may cause injury to the operator and/or surroundings.

There are five major crack detection methods or Non-Destructive Testing (NDT) listed in this section: Visual Surface Inspection (VT), Liquid Penetrant Testing (PT), Dry / Wet Magnetic Particle Testing (MPT), and Ultrasonic Testing (UT).

Crack detection methods or NDT is methods for testing components for cracks without damaging the component. VT, PT, Dry/ Wet MPT, and UT are methods recommended. There may be more than one acceptable crack detection method for the testing of a given part, although PT is the most versatile. For example, the PT method can be used when testing smooth machined components such as shafts, gear teeth, and splines, but using the Wet MPT is more accurate. Refer to Table 12 for advantages and disadvantages and Table 13 for standards and requirements for these NDT methods.

Table 12

Crack Detection Methods Advantages vs. Disadvantages
Detection Method	Advantages	Disadvantages
Visual Surface Inspection (VT)	- Least Expensive - Detects most damaging defects. - Immediate Results - Minimum part preparation	- Limited to surface-only defects. - Requires inspectors to have broad knowledge of welding and fabrication in addition to Non-Destructive Testing (NDT).
Liquid Penetrant Testing (PT)	- Inexpensive - Minimal Training - Portable - Works on nonmagnetic material.	- Least Sensitive - Detects surface cracks only. - Rough or porous surfaces interfere with test
Dry Magnetic Particle (MPT)	- Portable - Fast/Immediate Results - Detects surface and subsurface discontinuities	- Works on magnetic material only. - Less sensitive than Wet Magnetic Particle Testing (MPT).
Wet Magnetic Particle (MPT)	- More sensitive than Liquid Penetrant Testing (PT). - Detects subsurface as much as 0.13 mm (0.005 inch).	- Requires power for light. - Works on magnetic material only. - Liquid composition and agitation must be monitored.
Ultrasonic Testing (UT)	- Most Sensitive - Detects deep material defects. - Immediate Results - Wide range of materials and thickness can be inspected	- Most Expensive - Requires operator training and certification. - Surface must be accessible to probe

Table 13

Applicable Crack Detection Standards
Detection Method	Standard	Acceptance Criteria	Minimum Required Personnel Qualifications
Visual Surface Inspection (VT)	EN-ISO 5817 AWS D1.1	EN-ISO 5817 - Level B AWS D1.1 - Table 6.1	EN-ISO 9712 ANSI-ASNT SNT-TC-1A
Liquid Penetrant Testing (PT)	EN-ISO 3452 ASTM E165	EN-ISO 23277 AWS - D1.1	EN-ISO 9712 ANSI-ASNT SNT-TC-1A
Magnetic Particle Testing (MPT)	EN-ISO 17638 ASTM E709	EN-ISO 23278 - Level 1 AWS D1.1 - Table 6.1	EN-ISO 9712 ANSI-ASNT SNT-TC-1A
Ultrasonic Testing (UT)	EN-ISO 17640 - Level B AWS D1.1	EN-ISO 11666 Technique 2 - Level 2 AWS D1.1 - Class A - Table 6.3	EN-ISO 9712 ANSI-ASNT SNT-TC-1A

Visual Surface Inspection (VT)

Illustration 36	g06124166
Example of Visual Surface Inspection (VT) Tooling (A) Flashlight (or adequate light source) (B) Magnifying Glass (C) Tape Measure (or other measuring device) (D) Inspection Mirror

Refer to Tooling and Equipment Table3 for part numbers.

Components and welds that are to be tested using PT, MPT, or UT shall first be subject to a Visual Surface Inspection (VT). VT is often the most cost-effective inspection method and requires little equipment as seen in Illustration 36. Personnel performing VT shall either be trained to a company standard or have sufficient experience and knowledge regarding the components being inspected. Personnel performing VT shall take routine eye exams.

Liquid Penetrant Testing (PT)

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Personal injury can result from improper handling of chemicals. Make sure you use all the necessary protective equipment required to do the job. Make sure that you read and understand all directions and hazards described on the labels and material safety data sheet of any chemical that is used. Observe all safety precautions recommended by the chemical manufacturer for handling, storage, and disposal of chemicals.

Materials and Equipment Required

Refer to Tooling and Equipment Table3 for part numbers.

• Cleaner: Removes dirt before dye application and dissolves the penetrant making possible to wipe the surface clean.

• Penetrating Oil: This solution is highly visible, and will seep into openings at the surface of a part with capillary action.

• Developer: Provides a blotting action, bringing the penetrant out of the discontinuities and providing a contrasting background to increase the visibility of the penetrating oil indications.

• Wire Brush: Removes dirt and paint.

• Cloth or Wipes: Use with cleaner and for other miscellaneous uses.

Procedure

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Illustration 37	g06103795
Typical example of pre-cleaning the testing area.

1. Preclean the area to be tested. Spray on cleaner/ remover to loosen any scale, dirt, or any oil. Wipe the area to be tested with a solvent dampened cloth to remove remaining dirt and allow the area to dry. Remove paint where there are visible cracks using paint remover or a wire brush.
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   Illustration 38	g06103803
   Typical example of applying penetrating oil to areas to be tested.

2. Apply penetrant by spraying to the entire area to be tested. Allow 10 to 15 minutes for penetrant to soak. After the penetrating oil has been allowed to soak, remove the excess penetrating oil with clean, dry wipe.
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   Illustration 39	g06103816
   Typical example of removing penetrating oil with a cloth.

3. The last traces of penetrating oil should be removed with the cleaner solvent dampened cloth or wipe. Allow the area to dry thoroughly.
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   Illustration 40	g06103820
   Typical example of applying the developer.

4. Before using developer, ensure that the developer is mixed thoroughly by shaking the container. Hold the container approximately 203 - 305 mm (8.0 - 12.0 inch) away from the testing area. Apply an even, thin layer of developer over the testing area. A few thin layers are a better application method than one thick layer.
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   Illustration 41	g06084042
   Typical example of cracks found during Liquid Penetrant Testing (PT).

5. Allow the developer to dry completely for 10–15 minutes before inspecting for cracks. Defects will show as red lines in white developer background, refer to Illustration 41. Clean the area of application of the developer with solvent cleaner.

Dry Magnetic Particle Testing (MPT)

Materials and Equipment Required

Refer to Tooling and Equipment Table3 for part numbers.

Illustration 42	g06085930
(A) Indications shown by Dry Magnetic Particle Testing (MPT). (B) Electromagnetic Yoke (C) Dry Powder Bulb

1. Dry magnetic powder shall be of high permeability and low retentively and of suitable sizes and shapes to produce magnetic particle indications. The powder shall be of a color that will provide adequate contrast with the background of the surface being inspected.

2. Dry magnetic particles shall be stored in suitable containers to resist contamination such as moisture, grease, oil, non-magnetic particles such as sand, and excessive heat. Contaminants will manifest in the form of particle color change and particle agglomeration. The degree of contamination will determine further use of the powder.

3. Dry magnetic powder shall be tested in accordance with ASTM E709 Section 18 (Evaluation of System Performance/Sensitivity) when not performing.

4. Equipment should include a "U" shaped electromagnetic yoke made from highly permeable magnetic material, which has a coil wound around the yoke. This coil carries a magnetizing current to impose a localized longitudinal magnetic field into the part. The magnetizing force of the yoke is related to the electromagnetic strength and can be tested by determining the lifting power of a steel plate. The yoke shall have a lifting force of at least 4.5 kg (10 lbs).

5. Check dry powder blower routinely to ensure that the spray is a light, uniform, dust-like coating of the dry magnetic particles. Blower should also have sufficient force to remove excess particles without disturbing those particles that are evidence of indications.

6. All equipment shall be inspected at a minimum of once a year or when accuracy is questionable.

Procedure

1. Ensure surface to be inspected is dry and free from oil, grease, sand, loose rust, mil scale, paint, and other contaminants.

2. Apply the magnetic field using the yoke against the faces and inside diameter of each bore.

3. Simultaneously apply the dry powder using the dry powder blower.

4. Remove excess powder by lightly blowing away the dry particles.

5. Continue around the entire circumference of each bore. Position the yoke twice in each area at 1.57 rad (90°) to ensure that multiple directions of the magnetic field are created.

6. Observe particles and note if any clusters of particles appear revealing an indication.

7. Record the size and shape of any discontinuities or indications found.

Wet Magnetic Particle Testing (MPT)

Materials and Equipment

Refer to Tooling and Equipment Table3 for part numbers.

Illustration 43	g06085937
(A) Indications shown by Wet Magnetic Particle Testing (MPT). (B) Electromagnetic Yoke (D) Ultraviolet Lamp

Illustration 44	g06003178
Pear Shaped Centrifuge Tube

1. Wet magnetic particles are fluorescent and are suspended in a vehicle in a given concentration that will allow application to the test surface by spraying.

2. Concentration:

   1. The concentration of the suspended magnetic particles shall be as specified by the manufacturer and be checked by settling volume measurements.

   2. Concentrations are determined by measuring the settling volume by using an ASTM pear shaped centrifuge tube with a 1 mL (0.034 oz) stem with 0.05 mL (0.0017 oz) divisions, refer to Illustration 44. Before sampling, the suspension shall be thoroughly mixed to assure suspension of all particles, which could have settled. A 100 mL (3.40 oz) sample of the suspension shall be taken and allowed to settle for 30 minutes. The settling volume should be between 0.1 mL (0.0034 oz) and 0.25 mL (0.0085 oz) in a 100 mL (3.40 oz) sample.

   3. Wet magnetic particles may be suspended in a low viscosity oil or conditioned water.

   4. The oil shall have the following characteristics:

      • Low viscosity not to exceed 5 mm²/_s (5 cSt) at any temperature at which the vehicle is to be used.

      • Low inherent fluorescence and be non-reactive.

   5. The conditioning agents used in the conditioned water shall have the following characteristics:

      • Impart good wetting characteristics and good dispersion.

      • Minimize foaming and be non-corrosive.

      • Low viscosity shall not exceed a maximum viscosity of 5 mm²/_s (5 cSt) at 38° C (100° F).

      • Non-fluorescent, non-reactive, and odorless.

      • Alkalinity shall not exceed a pH of 10.5.

3. Equipment should include a "U" shaped electromagnetic yoke made from highly permeable magnetic material, which has a coil wound around the yoke. This coil carries a magnetizing current to impose a localized longitudinal magnetic field into the part. The magnetizing force of the yoke is related to the electromagnetic strength and can be tested by determining the lifting power of a steel plate. The yoke shall have a lifting force of at least 4.5 kg (10 lbs).

Procedure

1. Ensure surface to be inspected is dry and free from oil, grease, sand, loose rust, mil scale, paint, and any other contaminants.

2. Apply the magnetic field using the yoke against the surface in the area to be inspected.
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   Illustration 45	g03536210

3. For case hardened and ground surfaces:

   • Due to the sensitivity required to locate the grinding cracks, inspection of case hardened and ground surfaces require that the yoke is applied so that the magnetic field is 1.57 rad (90°) to the expected direction of the indications. Also, due to the increased sensitivity resulting when the yoke is energized, the yoke is not moved until the evaluation is completed in the first direction. An AC yoke shall be used. See Illustration 45 for an example of yoke placement.

4. Visually inspect for indications of discontinuities using the proper illumination.

5. Record the size and shape of any discontinuities found.

Ultrasonic Testing (UT)

Note: Crack depth cannot be accurately determined by UT, only full depth cracking can be consistently determined. For cracks that are not full depth, an indication of a partial depth cracks can be detected by an experienced technician. Refer to Table 13 for crack detection standards.

Refer to Tooling and Equipment Table3 for part numbers.

1. Ultrasonic Testing (UT) is a method of Non-Destructive Testing (NDT) using short ultrasonic pulse waves (with frequencies from 0.1-15 MHz up to 50 MHz) to detect the thickness of the object. Ultrasonic testing consists of an ultrasound transducer connected to a diagnostic machine and passed over the object being inspected.

2. There are two methods of receiving the ultrasound waveform from the transducer: reflection and attenuation.

   1. Reflection - Ultrasonic pulses exit the transducer and travel throughout the thickness of the material. When the sound waves propagate into an object being tested, the waves return to the transducer when a discontinuity is discovered along the sonic path. These waves continue and reflect from the back surface of the material to project the thickness of the material.

   2. Attenuation - A transmitter sends ultrasound through one surface, and a separate receiver detects the amount that has reached the transmitter on another surface after traveling through the medium. Any discontinuities or other conditions within the medium will reduce the amount of sound transmitted, revealing the presence of the imperfections.