Inspection of Rim Assemblies of Off-Highway Trucks {4201, 4209} Caterpillar

Introduction

© 2020 AVSpare 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 AVSpare: 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 AVSpare dealers and customers to benefit from cost reductions. Every effort has been made to provide the most current information that is known to AVSpare. 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 AVSpare.

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

Utilize the Dealer Solution Network (DSN) for urgent issues or questions concerning additional repair options or modifications to reuse and salvage techniques and/or methods.

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. AVSpare 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 AVSpare 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.

AVSpare 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. AVSpare dealers can supply the most current information.

Summary

The guideline provides fundamental procedures for the maintenance and inspection of rims. The information is intended as a guideline to minimize risks that are associated with the Off-Highway Truck tire and rim assemblies. The information is intended as a guideline to maximize the life of tires and rims. Detailed procedures may vary with the particular rim that is involved. Off-Highway Truck wheel and rim assemblies are often exposed to loads at the maximum capabilities of the assemblies or close to the maximum capabilities of the assemblies. Variations in haul roads can result in higher than normal loads on wheels. High cyclic stress can be generated in rim assemblies by hauling with vehicles that have not been loaded evenly. This stress can also be caused by hauling with vehicles with under inflated tires and hauling downhill with high speed turns, resulting in reduced fatigue life. Furthermore, the effects of corrosion and fretting between mating parts of a rim assembly can produce surface irregularities. These irregularities result in the initiation of cracks at different sites that ultimately result in the fracture of a rim part.

References

Service Advisories, Service Letters, and Technical Service Bulletins

Tooling and Equipment

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.

Preparation Recommendations

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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.

Note: Clean exterior of the rim assembly prior to disassembly.

• Before you inspect a part, clean the part thoroughly to ensure that all components are free from rust, oil, burrs, and debris prior to inspection. A surface irregularity can hide the indication of an unacceptable defect.

• Use a proper lifting device to provide safety to the operator. Also, use a proper lifting device to prevent damage to the part when you lift the part.

• During cleaning, do not damage machined surfaces.

• Do not use pressurized air to dry internal components. Compressed air has moisture and contaminants that can cause premature failure of internal components.

• Put hydraulic oil on all machined surfaces to prevent rust or corrosion if inspection is not done immediately after cleaning. Carefully store the parts in a clean container.

• Inspect all flange mating surfaces for fretting. Ensure that flange mating surfaces are true and free from raised material resulting from rust, nicks, and dents.

• Use appropriate thread taps to chase all threaded holes.

Visual Testing of the Rim Assembly

Illustration 3	g01390792
Typical rim assembly (1) Flange (2) Weld (3) Center section (4) Disc of rim (5) Groove on lock ring (6) Lock ring (7) Bead seat band (8) Back section (9) Radius of back section (10) Rim base

The following list of components of the rim assembly can be visually inspected for damage at each changing of the tires:

1. Lock Ring (6) - Inspect the lock ring for wear, corrosion, flat spots, and warping. In the free state, or the disassembled state, the lock ring must have overlap of the two ends.

2. Bead Seat Band (7) - Inspect the bead seat band for wear, corrosion, and cracks in the areas of contact with the lock ring, flange, base rim, or any weld.

3. Flanges (1) - Inspect the flanges for wear, corrosion, cracks, fretting, and general damage.

4. Rim Base (10) - Inspect the rim base for wear, corrosion, cracks, fretting, and general damage. The inside area of the rim shall be visually inspected for corrosion.

Note: Parts that are cracked, worn, damaged, or pitted from corrosion shall not be reused and these parts shall be rendered unusable and discarded. Consult your AVSpare Dealer if you have any questions on the acceptability of parts.

Magnetic Particle Testing of the Rim Assembly

To perform a magnetic particle inspection, the tires must first be removed. Magnetic particle inspection should be performed when accumulated service hours on the rim have reached 12,000 to 15,000 hours. The inspection should be performed at every following 12,000 to 15,000 hour interval.

Note: If any damage is found during visual inspection, magnetic particle inspection may be needed sooner than 12,000 hours on some rims.

Check the following areas of the rim:

1. Welds on Center Section (3)

2. Butt welds

3. Welds on Disc of Rim (4)

4. Areas of contact with Flanges (1) and Radius of the Back Section (9)

5. Areas of contact with Lock Ring (6) and O-ring groove

The primary areas of high stress are the following areas:

1. Circumferential welds

2. Butt welds

3. Welds on Disc of Rim (4)

4. Radius of Back Section (9)

5. Groove on Lock Ring (5)

Note: Parts that are cracked, worn, damaged, or pitted from corrosion shall not be reused and these parts shall be rendered unusable and discarded. Consult your AVSpare Dealer if you have any questions on the acceptability of parts.

Note: This information is not intended to override compliance with any regulatory agency. If any regulatory agency requires an inspection of the rim, this information can be used as a guideline.

Crack Detection Methods

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

Crack detection methods or NDT is methods for testing components for cracks without damaging the component. VT, PT, and Dry/ Wet MT 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 MT is more accurate. Refer to Table 4 for advantages and disadvantages and Table 5 for standards and requirements for these NDT methods.

Visual Testing (VT)

Illustration 4	g06085008
Example of Visual Testing (VT) Tooling (A) Flashlight (or adequate light source) (B) Magnifying Glass (C) Tape Measure (or other measuring device) (D) Inspection Mirror (E) Weld Size Inspection Gauges

Refer to Tooling and Equipment Table 3 for part numbers.

Components and welds that are to be tested using PT, or MT shall first be subject to Visual Testing (VT). VT is often the most cost-effective inspection method and requires little equipment as seen in Illustration 4. 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 Table 3 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 5	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 6	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 7	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 8	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 9	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 9. Clean the area of application of the developer with solvent cleaner.

Dry Magnetic Particle Testing (MT)

Materials and Equipment Required

Refer to Tooling and Equipment Table 3 for part numbers.

Illustration 10	g06085930
(A) Indications shown by Dry Magnetic Particle Testing (MT). (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 to reveal an indication.

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

Wet Magnetic Particle Testing (MT)

Materials and Equipment

Refer to Tooling and Equipment Table 3 for part numbers.

Illustration 11	g06085937
(A) Indications shown by Wet Magnetic Particle Testing (MT). (B) Electromagnetic Yoke (D) Ultraviolet Lamp

Illustration 12	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 12. 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 13	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. Refer to Illustration 13 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.