Reusability Guidelines for Single Tooth Master Links {0729, 4150, 4169, 4171} Caterpillar

Caterpillar Products

Machines with Sleeve Bearing Track

Track-Type Tractor

D10N (S/N: 2YD1-UP; 3SK1-UP)

D10R (S/N: 3KR1-UP; AKT1-UP)

D10T (S/N: RJG1-UP)

D10T2 (S/N: RAB1-UP; JJW1-UP)

Introduction

© 2019 Caterpillar All Rights Reserved. This guideline is for the use of Caterpillar 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 Undercarriage Reconditioning Bulletin 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 Undercarriage Reconditioning Bulletin must be used with the latest technical information that is available from Caterpillar.

For technical questions when using this document, work with 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.

Summary

Master links and master bolts are the most sensitive components of the track link assembly. When track type machines are in operation, there is a load concentration in the master links and bolts. Several factors can contribute to master link failure. Master link failure will cause track separation. Factors that contribute to master link failures are listed below.

• The condition of contact surfaces between heads of the master bolts and the master shoes.

• The condition of mating surfaces of the master shoes, master links, and the link halves.

• The condition of the threads in the link halves and on the master bolts.

• The torque value and method used on the master bolts.

Note: When a link assembly is brought into the shop for scheduled repair or reconditioning, some components will have small cracks and abrasion. The abrasion and cracks cannot be seen during disassembly. A careful inspection of each component is essential. Use a magnifying glass, dye penetrant, or magnetic particle tester to aid in the inspection.

References

Safety

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.

This bulletin may contain hazardous steps. A safety alert symbol like the one below is used to identify a hazard.

Warning messages identify a specific, imminent, latent, hazard that has a reasonable probability of resulting in personal injury or death if the warning is ignored.

Illustration 1	g02139237

Show/hide table

Do not attempt to disassemble or assemble this machine until you read and understand the disassembly and assembly instructions. Improper disassembly and assembly procedures could result in injury or death.

Show/hide table

Inspect all threaded components before use. Damaged threads may fail under hydraulic pressure. Broken threads may release flying objects that are propelled with great force. Personal injury or death can occur if struck by flying objects.

Show/hide table

Do not stand near the hydraulic press while the press is in operation. A component that slips or breaks under pressure may fly into the air with great force. Personal injury or death can occur if struck by flying objects.

Canceled Part Numbers and Replaced Part Numbers

This document may not include all canceled part numbers and replaced part numbers. Use NPR on SIS for information about canceled part numbers and replaced part numbers. NPR will provide the current part numbers for replaced parts.

Tooling and Equipment

Reusability Guidelines

Reusing master links when possible can reduce undercarriage costs. Inspect master links every time you service the track link assemblies. During a repair or reconditioning, correct any conditions that could have caused the original master links to fail.

Use the following criteria to determine if the master links can be reused:

• Master links should only be reused as matching sets. If either half cannot be reused, discard both halves. If one master link is replaced, the other adjoining master link should be replaced. Replacing the adjoining master link will avoid twisting of the track caused by unequal wear.

• Do not reuse master links halves if the halves have been welded together.

• Do not reuse master links if part of the tooth is missing.

• Do not reuse master links that have one or more cracks. The cracks may be small and difficult to detect. To detect the cracks, the link is to be thoroughly cleaned and inspected.

• Do not reuse the split master links if the contact surfaces contain burrs and raised areas. Remove all burrs and raised areas, which may cause interference between mating halves before reusing the master link. Use a polishing stone or file to remove cold flowed material, eliminating interference between mating halves.

Illustration 2	g03182516

Refer to Illustration 2. The arrow on the upper left represents the bushing end master half link. The arrow on the lower right represents the pin end master half link.

Illustration 3	g03177820

The circle in Illustration 3 references the surfaces where master half links meet near the rail.

Illustration 4	g03177845

Uneven surfaces where bushing end master half links meet at the rail is normal wear.

Illustration 5	g03177855

Uneven surfaces where pin end master half links meet at the rail.

Illustration 6	g03182239

Illustration 6 represents the master link before the removal of the uneven surfaces. The master links halves are contacting one another in the circled location. This contact will not allow proper engagement between the mating surfaces of the master link halves when assembled.

Illustration 7	g03177968

Grind the uneven surfaces smooth where master half links meet at the rail. Only remove what is necessary to provide clearance.

Illustration 8	g03182249

Uneven surfaces have been removed and the master link halves are independent of one another in the circled location and are salvaged for reuse.

Illustration 9	g03179158

Refer to Illustration 9. The arrows are pointing to the mating surfaces between the two master half links. Mating surface areas of assembled master link halves should not contain a gap or breach. Removing any nicks or burrs from these surfaces will allow the mating surfaces between the two master half links to engage properly allowing for proper retention. The circle references the surfaces where master half links meet at the rail. No contact within the circled area is allowed for reuse.

Illustration 10	g03177869

Normal sprocket wear into bushing end master link half. No grinding or polishing of this worn area is necessary. Recommended to reuse link.

Illustration 11	g03179437

Area that references bushing end eyebrow wear (inside red box). Refer to Illustration 11.

Illustration 12	g03179519

Bushing end eyebrow wear caused from track thrust (top arrow) in Illustration 12. Track thrust initiated a raised area on the tooth ramp surface below the trailing edge master bolt hole (bottom two arrows) in Illustration 12. This raised area must be removed for reusability. Use a polishing stone or file the raised area smooth on the surface below trailing edge master bolt hole prior to reuse.

Illustration 13	g03178006

Rust and scale on the mating surface of the master link halves.

Illustration 14	g03179400

Wire wheel or wire brush the rust and scale from the mating surface of the master link halves. Mating surface of master link halves are required to be clean and in good condition for reuse.

Illustration 15	g03177959

Use a tap to clean all master link threads and wash out any debris left in the threads before reuse.

Illustration 16	g03177951

Threads should be clean and in good condition. Refer to Illustration 16.

Do not reuse the master links if the threads are damaged.

Illustration 17	g03201950

Check the threads for damage by using a new master bolt. Apply anti-seize to the threads of the new master bolt. Thread the new master bolt into the bore by hand. A hand tool may be used but no power tools should be used. Ensure that the master bolt will travel to the bottom of the bore threads. Refer to Illustration 17. If the bolt does not thread into the master link by hand, discard the master link. If the master bolt does thread into the master link by hand, reuse the master link.

Illustration 18	g03177979

Inspect bolts for stripping, galling, and cracking.

Illustration 19	g03179937

Bolts can be reused if the bolts are clean and in good condition, examine the threads closely.

Illustration 20	g03182956

The master link halves will be assembled during the installation of the track link assembly on the machine. The mating surfaces of both the pin and bushing end master link halves will become fully engaged with one another. There must be no more than 2.0 mm (0.079 inch) of misalignment between the sides of the forged surfaces of the pin and bushing end master link halves. Refer to Illustration 20 the (four red arrows). If there is more than 2.0 mm (0.079 inch) of misalignment, the misalignment must be corrected before proceeding.

Surface Flatness Inspection

A tool developed by Caterpillar and procedure has been created to assist with the inspection of single tooth master link surface flatness for the Track-Type Tractor models D10 and D11. For tooling part number reference Illustration 22.

During machine operation with loose master bolts, the mating surfaces of each master link half may experience wear between the mating surfaces which results in less than acceptable surface contact area between the surfaces.

Illustration 21	g06145066

Reuse of master links in this condition will result in master track bolt loosening prematurely. To prevent these failures from occurring, Caterpillar recommends using this inspection procedure to determine if a master link should be reused.

Illustration 22	g06144687
Tooling used for surface flatness inspection (1) Gage Pin 561-2022 (2) Probe 6V-9408

Illustration 23	g06144683

The tool is designed such that one side can be used for D10 inspections, and the other side is sized for D11 inspections. The tool inserts into each bolt hole. Inserting the 6V-9408 through the tool cross hole allows the critical surface surrounding each bolt hole to be inspected for irregular wear.

Inspection Process

Illustration 24	g06145049
Irregular surface wear should be measured at each location by using a standard feeler gage.

Illustration 25	g06145053
Irregular surface wear should be measured at each location by using a standard feeler gage.

Clean master link mating surfaces to ensure that the inspection process will be efficient. Using a standard feeler gauge, irregular surface wear should be measured at each location. The maximum allowable gap between the pin and link mating surface should not exceed 0.15 mm (0.006 inch) within the outer 9.5 mm (0.375 inch) of the machined surface. If the gap exceeds 0.15 mm (0.006 inch), the link half should not be reused. Always replace both pin end master link and bushing end master link as pairs when replacement is necessary. Repeat this procedure to Inspect each master link half using the same dimensions.

Alternate Inspection Process

Illustration 26	g06145011

The master links can also be inspected while assembled. Ensure that all master link bolts are in place and torqued to the required pre-torque values in the Table 4. Using a standard feeler gauge, surface wear should be measured at each bolt location from the inside and outside of each link. Maximum allowable gap between the link mating surfaces should not exceed 0.30 mm (0.012 inch) at the maximum depth of 9.5 mm (0.375 inch) from the outer link surface. If the gap exceeds 0.30 mm (0.012 inch) at maximum depth of 9.5 mm (0.375 inch), the link halves should not be reused.

Reuse of master links in this condition will result in master track bolt loosening. Always replace both pin end master link and bushing end master link as pairs when replacement is necessary.

Master Link Thread Inspection

Master link bolt threads should be inspected if bolts have been found to be loose or missing. The movement of the master links during operation can damage the internal threads.

Clean the master link bolt threads by using the recommended clean out tap in Table 5. Use a solvent cleaner or air to remove loose debris from the bolt holes.

Illustration 27	g06145032

Using a new master link bolt, hand tighten the new bolt until it contacts the bottom of the threaded hole. Back the bolt out one complete revolution from the bottom. Use a magnetic base dial indicator as shown in Illustration 27, record the total side to side movement of the bolt. The total side to side movement should not exceed 4 mm (0.16 inch). Repeat the procedure on the remaining threaded bolt holes. If any of the threaded bolt holes are in excess of 4 mm (0.16 inch) total indicator reading, the master links should not be reused. Reuse of master link and bushing end master link as pairs when replacement is necessary.

Shipping Recommendations

Illustration 28	g03178015

If the track link assemblies or loose links are being shipped without the master shoes and bolts attached, reuse shipping plugs to protect the threads. For D11 reuse shipping plugs 344-2309 and for D10 397-4093 if the threads on the plugs are not damaged. Refer to Illustration.28