Clutch Ring Gears For Power Shift Transmissions for Certain Models {3030, 3155} 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

Follow all safety warnings. Most accidents that involve product operation, maintenance, or repair are caused by failure to observe safety warnings. An accident can often be avoided by recognizing potentially hazardous situations before an accident occurs. Personnel must be properly trained to perform maintenance, repair, or operate any machine. Safety precautions and warnings are provided this instruction and on AVSpare products. These warnings should be observed before performing any procedures. AVSpare cannot anticipate every possible circumstance that might involve a potential hazard. The warnings in this publication and on the product are not all inclusive.

The hazards are identified by the “Safety Alert Symbol” which is followed by a “Signal Word” such as “DANGER”, “WARNING” or “CAUTION”. The “WARNING” Safety Alert Symbol is shown in Illustration 2.

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

This guideline provides the procedures necessary to determine the reusability of the clutch ring gear. Life will vary depending on application, load, lubrication, and environment.

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

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 clutch ring gears prior to disassembly to minimize cross-contamination.

• 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.

Standardized Parts Marking Procedure

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.

Illustration 3	g06124077
DO NOT use numbering stamp punches to mark internal components.

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 4	g03856853
Typical Example

Illustration 4 shows code (1-15). The first number (1) indicates that the gear had been rebuilt once. The second number (15) indicates that there were 15,000 hours on the gear at the time of rebuild.

Example 2

Illustration 5	g03856857
Typical Example

Illustration 5 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 gear had been rebuilt twice. The second number (10) indicates that 10,000 hours accumulated on the gear between the first and second rebuild.

Note: Add the first and second rebuild hours to obtain the total number of hours for the gear in Illustration 5. In this example, the gear has a total of 22,000 hours.

Illustration 6	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

Reusability of clutch ring gears depends on the degree of damage or wear. Some damaged clutch ring gears obviously cannot be used again. Other gears can be used again, some with certain limitations. For example, gears with heavy wear on the inner teeth, as shown in Illustration 7, can be used again if an increased noise level is acceptable.

Illustration 7	g02155413
Heavy wear on the face of the inner teeth.

OK TO USE PART AGAIN. Depending on the location and degree of damage, some damaged clutch ring gears can be reused without limitations. The four most common types of damage which do not necessarily affect use are:

• Wear of the ring gear side face

• Wear on the crowns of the outer teeth

• Notches on the faces of the outer teeth

• Damage caused by debris

Wear on the Ring Gear Side Face

Illustration 8	g02155414
Normal wear on the side of the ring gear.

The arrow shows normal wear on the side face of a ring gear, OK TO USE PART AGAIN.

The ring gear is held in a center position by the clutch housing. The wear on the side face shows the area of ring gear contact with the clutch housing. The size of the worn area can change around the ring gear. This change is not an indication that the ring gear has been bent from the original shape. Places where no wear has taken place are indications of low areas. Clutch ring gears that have the above characteristics of side face wear can be used again.

Wear on the Crowns of the Outer Teeth

Illustration 9	g02155416
A broken clutch disc can score (make marks), or put grooves in the tips of the outer teeth on the ring gear. (1) Score Marks

If the damage is similar to the score marks (1), as shown in Illustration 9, then OK TO USE PART AGAIN.

A ring gear can be used again if the crowns of the outer teeth show score marks.

Illustration 10	g02155417
A broken clutch disc can score (make marks), or put grooves in the tips of the outer teeth on the ring gear. (2) Deep Grooves

If the damage is similar to the deep grooves (2), as shown in Illustration 10, then DO NOT USE PART AGAIN.

A ring gear cannot be used again if the crowns of the outer teeth have deep grooves.

Illustration 11	g02155420
Ring gear with notches on the faces of the outer teeth and a groove across several teeth.

After the notches are measured and found to be acceptable, then OK TO USE PART AGAIN.

Refer to Illustration 11 that shows a ring gear with a groove that runs across the width of the gear. This type of groove was made when the ring gear was machined. Ring gears that have this type of groove can be used again. Only a few teeth of each disc will come in contact with the groove at one time.

Notches on the Faces of the Outer Teeth

The load of the clutch discs on the outer teeth of the ring gear causes short notches on the faces of the outer teeth, refer to Illustration 11. Discs should be inspected to determine the depth of the notches. During operation, deep notches will cause incorrect separation between the clutch discs and plates. Friction will build, causing excessive heat in the clutch.

Although some clutches will function adequately with notches deeper than the limits shown below, the wear could exceed the hardened depth. Additional wear will be more rapid, especially if new clutch discs are used.

Use the following steps to determine if a ring gear with notches on the outer teeth can be used again:

1. Cut a piece of 0.13 mm (0.005 inch) thick shim stock to the dimension of 2.4 mm (0.09 inch) wide and 50.8 mm (2.00 inch) long. If 0.13 mm (0.005 inch) thick shim stock is not available, use a 0.13 mm (0.005 inch) thickness gauge (feeler gauge) can be cut to a length of 2.4 mm (0.09 inch).
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   Illustration 12	g02155424
   (A) Maximum width of shim stock

2. Put the piece of shim stock into a notch. The shim must fit into the bottom of the notch without contacting the sides of the notch that have a taper. Refer to Illustration 12. If the shim does not fit in the bottom of the notch, cut the shim to fit into the notch.
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   Illustration 13	g02155431
   Measure notches with shim stock.

3. Put a steel ruler or other straight edge across the face of the tooth, refer to Illustration 13. Ensure that the steel ruler is in contact at all places across the width of the face.

4. Hold the steel ruler in place and pull on the shim. Check the depth of all the notches in each of four teeth, 90° apart.

5. If you can pull the shim easily from any of the notches checked, then DO NOT USE PART AGAIN.

6. If you cannot pull the shim easily from any of the notches checked, then OK TO USE PART AGAIN.

Illustration 14	g02155434
(3) Flanged or Asymmetrical (4) Symmetrical

Refer to Illustration 14 for ring gear that is flanged or asymmetrical (3) and ring gear that is symmetrical (4) (same shape on both sides).

Symmetrical ring gears with notches in the outer teeth worn beyond the 0.13 mm (0.005 inch) maximum, can be used again.

Illustration 15	g02155455
Symmetrical ring gear that has been flipped. The upward arrow shows the notch. The downward arrow shows opposite face of the outer teeth.

To reuse a worn symmetrical ring gear, the ring gear may be flipped so that the clutch discs contact with the opposite face of the outer teeth. Refer to Illustration 15.

Note: A ring gear that is asymmetrical cannot be flipped. If the notches in the outer teeth are worn beyond a maximum of 0.13 mm (0.005 inch), then DO NOT USE PART AGAIN.

Damage Caused by Debris

Raised areas, burrs, or rough edges on the gear teeth can be removed with Tooling as shown in Illustration 6 or with a polishing stone. Refer to Illustrations 16 18 for examples of this type of damage.

Illustration 16	g02155461
The arrow heads that shows the raised area or burrs. After raised areas and/or burrs are removed, then OK TO USE PART AGAIN.

Illustration 17	g02155814
The arrow heads that shows the raised area or burrs. After raised areas and/or burrs are removed, then OK TO USE PART AGAIN.

Be careful with burrs and gouges caused by debris, as shown in Illustration 18. After removing the high areas or rough edges, inspect the gears for cracks using Magnetic Particle Testing (MT). Refer to the "Crack Detection Methods" section.

At the time of assembly, ensure that the ring gears are still round. Best Practice: To check roundness of a ring gear, using a new disc determine if the disc will fit over the teeth without force. If force is not required to put the new disc on, then the ring gear is round.

Illustration 18	g02155815
Damage caused by debris.

After raised areas and/or burrs are removed, then OK TO USE PART AGAIN.

Crack Detection Methods

There are four major crack detection methods or Non-Destructive Testing (NDT) listed in this section: Visual Surface Inspection (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 Surface Inspection (VT)

Illustration 19	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 Table 3 for part numbers.

Components and welds that are to be tested using PT, or MT 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 19. 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.

• Penetration 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 20	g06084048
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 21	g06084053
   Typical example of applying penetrating oil to areas to be tested.

2. Apply penetrating oil by spraying to the entire area to be tested. Allow 10 to 15 minutes for penetrating oil 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 22	g06084060
   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 23	g06084070
   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 - 12 inch) away from part. Apply an even, thin layer of developer over the area being tested. A few thin layers are a better application method than one thick layer.
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   Illustration 24	g03773759
   Typical example of cracks found during Liquid Penetrant Testing (PT).

5. Allow the developer to dry completely for 10 to 15 minutes before inspecting for cracks. Defects will show as red lines in white developer background, refer to Illustration 24. 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 25	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 revealing 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 26	g06085937
(A) Indications shown by Wet Magnetic Particle Testing (MT). (B) Electromagnetic Yoke (D) Ultraviolet Lamp

Illustration 27	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 27. 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 28	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 28 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.