Procedure to Salvage Tang Slots on Transmission and Brake Pistons {0679, 3160, 4011, 4251} Caterpillar

Introduction

© 2019 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).

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.

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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 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.

During normal operation, wear occurs in the slots of transmission and brake piston tangs. Just as the slots become worn on clutch plates, the slots of the piston tangs also become indented on one or both sides. Refer to Illustration 4. This wear causes unnecessary circumferential movement that could cause an interference with the housing resulting in incorrect shifting or braking.

Refer to Table 4 for wear limits in the pin slots.

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.

Pin Slot Wear

Illustration 3	g02159962

Illustration 4	g06398914
Nomenclature for pin slot wear limits

Preparation

Thoroughly clean and de-grease the piston. Secure the piston in the vise. Use the die grinder and bit to buff the worn surface of the pin slot, prior to welding.

Salvage Procedure

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Illustration 5	g02159964
Worn Area

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Illustration 6	g02159973
Welded Area

1. Position the piston with the worn side of the slot downward. Use weld electrode to build up the worn area. Do not put an excessive amount of weld in the slot, higher than the unworn area. Refer to Illustrations 5 and 6.
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   Illustration 7	g02159974
   Slot ground flush with unworn surface.

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   Illustration 8	g02159975
   Completed piston with parallel sides.

2. Use the die grinder and bit to grind the weld flush with the unworn surface of the tang. Grind both sides of the tang and slot area. The ground surface in the pin slot should be parallel with the other side of the slot. The shot width should approximately be 0.25 mm (0.010 inch) to 0.38 mm (0.015 inch) larger than the reaction pin diameter. Refer to Illustrations 7 and 8.