- Caterpillar Products
- Machines with Grease Lubricated Track with Swage
- Machines with Greased Lubricated Track (GLT)
- Machines with Positive Pin Retention (PPR) Track
- Machines with Positive Pin Retention 2 (PPR2) Track
- Machines with Rotating Bushing Track
- Machines with Sealed Positive Pin Retention (PPR) Track
- Machines with Sealed Track
- Machines with Sleeve Bearing Track
- Machines with SystemOne Undercarriage
- Machines with non-PPR Sealed and Lubricated Track
- Machines with Greased Lubricated Track (GLT)
Introduction
Revision | Summary of Changes in SEBF8558 |
22 | Added serial number prefixes for New Product Introduction. |
21 | Added serial number prefixes for New Product Introduction. |
20 | Added serial number prefixes for New Product Introduction.
Updated introduction information. |
19 | Added serial number prefixes for New Product 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 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.
Summary
Lubricated track joints are required on all the larger Caterpillar Track-Type Tractors. Wet turns are recommended for all Sealed and Lubricated Tracks. Track sealability maintenance following dealer service is ensured only when all reused components meet the necessary standards. Reusing parts will keep costs at a minimum.
Grease Lubricated Track (GLT) was developed by Caterpillar to increase wear life of track for Hydraulic Excavators.
Wear life was improved by designing lubricated track pins and bushings.
This publication aids the operator of the track press and field mechanic in determining if components are reusable. The focus will be on wet turns. Most components are acceptable for dry turns. Pins that are spalled, cracked links, and cracked thrust rings are not reusable for a dry turn.
Before a track group can be properly inspected, clean the track group thoroughly. Links should be inspected for cracks before disassembly. All other components must be disassembled for proper inspection.
References
Reference: Undercarriage Reconditioning Bulletin, SEBF8557, "Sealed and Lubricated Track Service Procedure"
Reference: Undercarriage Reconditioning Bulletin, SEBF8546, "Shop Repair Procedure for Track Links with Positive Pin Retention"
Reference: Undercarriage Reconditioning Bulletin, SEBF8609, "Shop Repair Procedure for Sleeve Bearing Track"
Reference: Undercarriage Reconditioning Bulletin, SEBF8598, "Shop Repair Procedure for Grease Lubricated Track"
Reference: Undercarriage Reconditioning Bulletin, SEBF8612, "Field Service for Positive Pin Retention Track"
Reference: Undercarriage Reconditioning Bulletin, SEBF8613, "Field Service for Sleeve Bearing Track"
Reference: Undercarriage Reconditioning Bulletin, SEBF9100, "Field Repair of SystemOne Track with the Multi-Pitch Track Press"
Safety
Illustration 1 | g02139237 |
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 indicate 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.
Operating the track press incorrectly may result in a flying object hazard. Always operate the track press with protective guards installed and eye wear protection to prevent injury. Always read and understand the operator's manual for the track press before using. |
Canceled Part Numbers and Replaced Part Numbers
This document may include 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.
Nomenclature
Illustration 2 | g01825537 |
Sealed and Lubricated Track (1) Crosshole (2) Plug (3) Thrust ring (4) Load ring (5) Seal lip (6) Stopper (7) Bushing (8) Oil reservoir (9) Pin |
Illustration 3 | g01825695 |
Positive Pin Retention Track (1) Crosshole (2) Plug (3) Thrust ring (4) Retaining groove on the pin (5) Retaining ramp on the link (6) Spotface (7) Retaining ring (8) Load ring (9) Seal lip (10) Stopper (11) Bushing (12) Oil reservoir (13) Pin |
Illustration 4 | g01825773 |
SystemOne Track (1) Pin (2) Bushing (3) Thrust ring (4) Seals |
Illustration 5 | g01825899 |
Track Links (1) Retaining ring ramp (PPR only) (2) Spotface (PPR only) (3) Strut (4) Nut seat (5) Bushing bore (6) Bushing strap (7) Mating surface for the shoe (8) Rail surface (9) Link toenail (10) Pin bore (11) Seal counterbore (12) Pin boss |
Track Links
All major components of the track group are connected to the track link. See Illustrations 2,34, and 5. Track link design strives to balance structural strength with maximum wear life for most applications. Occasionally in low abrasive conditions, the link will be worn out structurally before all the wear material is gone. Structurally bad links will have cracks or stretched bushing bores.
Cracking in the Track Link
Illustration 6 | g01825976 |
Crack near the bushing strap |
Do not use the link again.
Illustration 7 | g01826013 |
Crack in the pin boss |
Do not use the link again.
Any link with a crack near the bushing strap should not be used again. Refer to Illustration 6 for a crack near the bushing strap. Refer to Illustration 7 for a crack in the pin boss. Yellow paint is often used to help detect any cracks.
Illustration 8 | g01826034 |
Crack in the link toenail |
Use the link again.
Cracks can occur in the link toenail. The link toenail is a thin section of material on the rail near the bushing strap. These cracks do not affect the structural integrity of the link. See Illustration 8.
Oversized Bushing Bores
High impact conditions can cause the bushing bore to elongate. This elongation will result in a loss of press fit between the bushing and link, which can adversely affect sealability.
Illustration 9 | g01826038 |
Rusted bushing bore |
Do not use the link again.
If the bushing bore is rusted and dirty all the way across the length of the bore. The press fit will be lost so the link must be discarded. See Illustration 9. The link is reusable if a shiny contact area is greater than
Damage to the Bushing Bore
Illustration 10 | g01826623 |
Bushings bore that is broached |
Use the link again.
Broached bushing bores are acceptable. The bushing bore and the bushing interface are not designed to seal oil. See Illustration 10. These links can be used again.
Spalling of the Track Link
Illustration 11 | g01826635 |
Spalling of the rail |
Use the link again.
Illustration 12 | g01826637 |
Spalling of the rail near the bushing strap |
Do not use the link again.
Pieces of hardened material will occasionally break off the rail surface. This break off is called spalling. See Illustration 11. Links with shallow spalling can be reused if less than one-third of the rail surface has broken off. Links with deep spalling near the bushing strap should not be reused. See Illustration 12.
Damage to the Link Counterbore
Illustration 13 | g01826675 |
Pitted counterbore that has been cleaned up |
Use the link again.
A seal failure will often lead to a damaged counterbore. Usually, links with pitted counterbores or corroded counterbores can be used again after cleanup. See Illustration 13.
Illustration 14 | g01826713 |
Link with an indentation from the thrust ring |
Use the link again.
Indentations from the thrust ring in the counterbore are normal. Links with an indentation from the thrust ring may be used again if the indentation is not deeper than
Damage to the Sidewall of the Link Counterbore
Illustration 15 | g01826694 |
Link with damage to the sidewall of the counterbore |
Use the link again if the height of the counterbore is greater than the installed height of the load ring.
Do not use the link again if the height of the counterbore is less than the installed height of the load ring.
Frequently, if a dry joint is allowed to run, the sidewall of the link counterbore will be damaged by contact with the bushing. See Illustration 15. The sidewall of the counterbore supports the load ring of the track. If too much material is worn off, the load ring will bulge in this area. Bulging of the load ring can cause premature failure. Links with damage to the sidewall of the counterbore may be reused only if the height of the counterbore in the damaged area is greater than the height of the installed load ring.
Roll Over on the Pin Boss
Illustration 16 | g01826753 |
Metal rolled over on the pin boss. |
Use the link again after the material is removed.
Contact with the flanges on the rollers will cause material to roll over on the pin boss. See Illustration 16. These links can be reused, but the material must be removed in order for the tooling on the track press to work properly.
Spotface for the Retainer Ring on PPR Track Links
Illustration 17 | g01826776 |
PPR link with damaged spotface |
Use the link again after the material is removed.
Contact with the flanges on the rollers or the track guards can sometimes roll material over the spotface surface on the link. This material may interfere with the tooling on the track press during assembly. See Illustration 17. This material should be removed before reassembly.
Broaching of the Pin Bore
Illustration 18 | g01826782 |
Pins bore with partial broaching |
Use the link again.
Illustration 19 | g01826781 |
Pin bore is broached |
Do not use the link again.
Damage on the pin or tool misalignment can cause the pin bore to be broached during Disassembly and Assembly. A pin bore that is broached is acceptable if the channel does not cut across the length of the bore. See Illustration 18. A pin bore that is broached the entire length of the bore is unacceptable. See Illustration 19. A leak path is created.
Note: Remove paint from the bores of new links to ensure proper sealability. A 222-3074 Wheel Grinder Gp with a 1U-9941 End Brush or 1U-9943 End Brush is recommended for removing paint from the link bores. Paint on the following mating surfaces must be removed to enable proper retention of the track shoe: link, shoe, nuts, bolts, and nut seats. 1U-6841 Abrasive Disk is recommended for removal of paint in larger flat areas such as the mating surface between the link and the shoe.
Track Pins
Track pins from dry joints should not be reused for wet turns. Pins from wet joints often contain damage. Inspect the pins before the pins are reused. A common place for damage is the area of the pin that contacts the bushing under load. This damage includes spalling, galling, and wear steps.
Pin Spalling
Illustration 20 | g01826792 |
Pin that is spalled |
Do not use the pin again.
Spalling is the flaking or breaking off pieces of the heat-treated case of the pin. See Illustration 20. Spalling weakens the pin structurally. Pins that are spalled should not be reused for wet turns or dry turns.
Pin Galling
Illustration 21 | g01826815 |
Pin that is galled |
Use the pin again.
Galling is caused by metal-to-metal contact. This contact results in scratches and grooves in a circumferential direction around the pin. See Illustration 21. Most pins that are galled can be reused if the extent of the galling is considered.
D11 Pin Galling
Illustration 22 | g01826837 |
D11 pin that is galled (A) Less than |
Use the pin again.
Illustration 23 | g01826839 |
D11 pin that is galled (B) More than |
Do not use the pin again.
D11 pins are different because the loads on the undercarriage components are greater. Therefore, do NOT reuse D11 pins that have a band of galling that is more than
Metal Transfer on Pins
Illustration 24 | g01826873 |
Metal transfer on pin |
Do not use the pin again.
Transferred metal on a pin end occurs when there is slight movement of the pin in the link bore. See Illustration 24. The metal is removed from the link and transferred to the harder surface of the pin. Pins with transferred metal should not be used again. The raised metal areas will cause the link bore to become broached as the pin is pressed into the bore. The broached area will allow a leak path in the pin bore.
Wear Step
Illustration 25 | g01826918 |
Pin with a slight wear step |
Do not use the pin again if a step can be felt.
A pin from a wet joint will occasionally exhibit a slight wear step. If this wear step is more than
Damage on the Pin End
Illustration 26 | g01827018 |
Damage on the pin end |
Use pin again after the chamfer is ground onto the pin end.
Damage on the pin end occurs during machine operation when the end of the pin comes in contact with the track guards or the flanges of the rollers. A damaged pin end can have sharp edges that could damage the pin bore during assembly. See Illustration 26. These pins are reusable after a 10 degree chamfer is ground on the damaged end.
Retainer Ring Groove for PPR track
Illustration 27 | g01827034 |
PPR pin with damage to the retainer groove |
Use the pin again.
Illustration 28 | g01827035 |
PPR pin with worn retainer groove |
Use the pin again.
Positive Pin Retention (PPR) track pins have grooves on the ends to accept retaining rings. The ends on PPR pins should not be chamfered. Some damage to the groove for the retaining ring on the pin is acceptable however, no more than 25% of the groove should be worn or broken away from the pin. Refer to Illustration 27 and Illustration 28.
Cracks in the Bushing
Illustration 29 | g01827042 |
Bushing with a crack on the inside diameter |
Do not use the bushing again.
Illustration 30 | g01827046 |
Bushing with cracks on the end |
Do not use the bushing again.
Bushings from dry joints cannot be used again for a wet turn. Bushings need to be carefully inspected for cracks. Refer to Illustration 29 and Illustration 30. A crack in a bushing will allow oil to leak. This results in dry joints. After cleaning, inspect the ID, OD, and the ends of the bushing.
End Grooving on the Bushing
Illustration 31 | g01827053 |
Bushing end with grooving gauge in place |
Do not use the bushing again if a groove is visible.
Illustration 32 | g01827055 |
Typical indications of the bushing groove gauge. |
The track seal fits in the link counterbore and seals against the bushing end. A groove can be formed in the end of the bushing. If the groove is too large, the track seal may not effectively seal against the damaged bushing end. Gauges for end grooving on the bushing are available to determine the reusability of grooved bushings. The gauge slips over the bushing ends. See Illustration 31. Rotate the gauge around the end of the bushing. Place the track bushing groove gauge on the bushing and determine if the seal groove has progressed enough that the groove is visible. If the seal groove is visible, the bushing should not be reused. See Illustration 32.
Galling in the ID of the Bushing
Illustration 33 | g01827173 |
Galled bushing |
Galling on the ID of the bushing occurs because of the lack of lubrication. See Illustration 33. Galling on the pin and the bushing usually occurs simultaneously. Galled bushings can occasionally be reused. Pins and bushings for the D11 should be evaluated for galling.
Use the bushing again if the galling on the ID of the bushing does not exceed
Do not use the bushing again if the galling on the ID of the bushing exceeds
Metal Transfer on Bushings
Illustration 34 | g01827274 |
Bushing with metal transfer on ends |
Use the bushing again.
The metal transfer on the bushing end occurs when there is slight movement of the bushing in the link bore. The metal that is removed from the link is then deposited on the harder surface of the bushing. A pin that has any metal transfer may not be used, because the pin to the pin bore must seal oil. Transferred metal on a bushing can be reused because the bushing to the bushing bore does not seal oil. See Illustration 34.
Damaged Thrust Rings
Illustration 35 | g01827277 |
Cracked thrust ring |
Do not use the thrust ring again.
The thrust ring allows the proper amount of compression of the track seal in the assembled joint. Thrust rings with any crack cannot be used again. See Illustration 35. Do not reuse thrust rings from dry joints for a wet turn.
Illustration 36 | g01827293 |
Severely chipped thrust ring |
Do not use the thrust ring again.
A heavily chipped thrust ring cannot be used again. See Illustration 36.
Worn Thrust Rings
Illustration 37 | g01827294 |
Thrust ring with minor damage |
Use the thrust ring again if the grooves for lubrication can be seen.
If the grooves for lubrication can be seen on both sides, a thrust ring with corrosion, grooves, or small chips on the faces can be used again. See Illustration 37. Do not reuse the thrust ring if the thrust ring is galled 360 degrees on either side.
SystemOne
The SystemOne track components and the previous conventional track components are different. Many of the concerns for reusability from the previous conventional undercarriage components are no longer an issue.
For any concerns with cracks in the track links, refer to the "Cracking in the Track Link" section.
The cartridge pin is preassembled. The cartridge pin contains the pin, the bushing, and the seals. Because the cartridge pin is permanently assembled from the factory, you can no longer inspect the pin, the bushing, or the seals.
Illustration 38 | g01827333 |
SystemOne components (1) Cartridge pin (2) Link bore |
Use the components again.
If the bore of the track link has been broached, the track link is acceptable for reuse. Transferred metal on the cartridge pin and the link bore is reusable. See Illustration 38.
If any concerns arise about the reusability of the SystemOne track components, contact Caterpillar Repair Process Engineering for more information.
Glossary
Broached - Material that is removed from the bore during assembly or disassembly. Broaching can be caused by a defect on the end of the pin or misalignment of tooling.
Cartridge pin - An assembly of the pin, bushing, and seals that is used exclusively on the SystemOne track
Chipped - Small pieces of material are removed from the component.
Circumferential - Similar to a circle
Dry Joint - A track joint that has lost lubricant because of a failure of the track seal, cracked bushings, or other reason
Dry Turn - A 180 degree turn of the bushings and pins assembled with the used seals, thrust rings, and no lubrication in the joints.
Elongation - The result of a condition that makes a hole in a component longer or wider in one direction
Flaked - The surface is worn by friction.
Galled - Pieces of the surface material have broken loose.
I.D. - Inner diameter of a cylindrical object
Mating - Parts that operate together
O.D. - Outer diameter of a cylindrical object
Pitted - The component contains small holes from corrosion.
Positive Pin Retention (PPR) - A type of track designed to eliminate end play by extruding rings between the track pins and links.
Scaled - Surface material is removed by corrosion.
Spalled - Chips of metal have broken loose from the contact area on the component.
SystemOne - A type of track that has improved joint retention, improved sealability, and requires a minimal amount of service.
Wear Step - The component is worn so that two surface levels can be felt.
Wet Joint - A track joint that has retained lubrication
Wet Turn - A 180 degree turn of the bushings and pins assembled with lubrication in the joints.