Reuse and Salvage of Transmission Components {3030} Caterpillar


Reuse and Salvage of Transmission Components {3030}

Usage:

769C 01X


Articulated Truck
All
Asphalt Paver
All
Backhoe Loader
All
Challenger
All
Cold Planer
All
Compact Track Loader
All
Compact Wheel Loader
All
Continuous Haulage
FH330 (S/N: FHY1-UP)
Dragline
All
Electric Rope Shovel
All
Forest Products
All
Hydraulic Shovel
All
Integrated Toolcarrier
All
Landfill Compactor
All
Motor Grader
All
Off-Highway Truck/Tractor
All
On-Highway Transmission
All
Petroleum Transmission
All
Pipelayer
All
Road Reclaimer/Soil Stabilizer
All
Track-Type Loader
All
Track-Type Skidder
All
Track-Type Tractor
All
Transmission
All OEM Transmissions
TH55FT-E70 (S/N: PCJ1-UP)
TH55FT-E90 (S/N: THE1-UP)
Underground Articulated Truck
All
Wheel Dozer
All
Wheel Loader
All
Wheel Skidder
All
Wheel Tractor-Scraper
All

Introduction

Table 1
Revision  Summary of Changes in SEBF8091 
13  Added new serial number prefixes for New Product Introduction (NPI). 
12  Added new serial number prefixes for New Product Introduction (NPI). 
11  Added serial number prefixes. 
10  Added media to tables. 
09  Added group effectivity for All OEM Transmissions. 

© 2018 Caterpillar 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 Caterpillar: 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 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 Reuse and Salvage Guideline 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.

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.

Summary

The contents of this guideline includes component reusability and some salvage procedures. Most of this guideline gives visual examples of parts that fall into the "Use again" or "Do not use again" categories. Subjects requiring more lengthy salvage procedures are contained in other published guidelines. These guidelines are listed in the "References" section.

Replacement of individual ring, planet, or sun gears in a planetary set is acceptable. It is recommended that all the planet gears be replaced together if the new gears have the same package date. Otherwise, individual gears can be replaced.

When used in the same application, parts that meet the "Use again" specifications in this and other guidelines can be expected to give normal performance until the next Planned Component Rebuild (PCR). Never install a part that this guideline shows cannot be used again. During reconditioning, correct any conditions that might have caused the original failure.

References

Prior to beginning the transmission repair, service personnel should also have on-hand the appropriate Service Manual and the following Reuse and Salvage Guidelines.

Table 2
References Material 
Media Number  Publication Type & Title 
SEBF8006  Reuse & Salvage Guidelines , "Clutch Housings and Clutch Pistons for Transmissions and Torque Dividers" 
SEBF8013  Reuse & Salvage Guidelines , "Transmission Clutch Plates and Disc Assemblies with Sintered Bronze Friction Material" 
SEBF8014  Reuse & Salvage Guidelines , "Identification and Applications of Transmission Clutch Plates and Specifications to Machine Reaction Faces for Power Shift Transmissions" 
SEBF8017  Reuse & Salvage Guidelines , "Clutch Ring Gears For All Power Shift Transmissions" 
SEBF8021  Reuse & Salvage Guidelines , "Transmission Bevel Pinion and Transfer Gear for D5, D6, D7, D8, and D9 Tractors with Oval Tracks" 
SEBF8028  Reuse & Salvage Guidelines , "Salvage Case Assembly and Idler Shaft in Transmission Transfer Gear Groups for 621B, 623B, 627, 627B, 641, 641B, 650B, 651B, 651E, 657, 657B, 657E, 657G, 660B, 666, and 666B Tractor-Scrapers" 
SEBF8031  Reuse & Salvage Guidelines Reuse & Salvage Guidelines , "Transmission Clutch Plates and Disc Assemblies with F37 and F37X Friction Material" 
SEBF8048  Reuse & Salvage Guidelines , "Procedure to Machine Damaged Transmission and Differential Yokes" 
SEBF8060  Reuse & Salvage Guidelines , "Repair of Transmission, Torque Converter and Torque Divider Shafts" 
SEBF8070  Reuse & Salvage Guidelines , "Bearing Bores in Hydrostatic Transmission Cases" 
SEBF8091  Reuse & Salvage Guidelines , "Reuse and Salvage of Transmission Components" 
SEBF8096  Reuse & Salvage Guidelines , "Transmission Governor Salvage for Seven and Eight Speed Powershift Transmissions" 
SEBF8098  Reuse & Salvage Guidelines , "Transmission Clutch Plates and Disc Assemblies with Rayflex Friction Material" 
SEBF8099  Reuse & Salvage Guidelines , "Repair of Reaction Dowel Holes in Transmission Clutch Housings" 
SEBF8114  Reuse & Salvage Guidelines , "Identification of Non-Metallic Discs that are Used in Power Shift Transmissions" 
SEBF8115  Reuse & Salvage Guidelines , "Transmission Clutch Plates and Disc Assemblies with Cellulose Friction Material" 
SEBF8116  Reuse & Salvage Guidelines , ""White Layer Flaking" of Transfer Gears in Off-Highway Trucks and Tractors" 
SEBF8134  Reuse & Salvage Guidelines , "Individual Clutch Modulation (ICM) Control Valves" 
SEBF8163  Reuse & Salvage Guidelines , "Procedures to Salvage Thrust Faces on Planetary Carriers" 
SEBF8173  Reuse & Salvage Guidelines , "Salvage of Transmission Transfer Gear Case and Cover for Articulated Trucks, Compactors, Load Haul Dump, Wheel Loaders, Wheel Tractors, and Motor Graders" 
SEBF8178  Reuse & Salvage Guidelines , "Procedure to Salvage Tang Slots on Transmission and Brake Pistons." 
SEBF8195  Reuse & Salvage Guidelines , "Salvage Procedure for 8E-2155, 6I-9430, 6I-9678 Transmission Covers" 
SEBF8257  Reuse & Salvage Guidelines , "Procedure to Salvage the Slots for the Pin and Holes for the Reaction Dowel in Transmission Clutch Plates, Pistons, and Housings" 
SEBF8332  Reuse & Salvage Guidelines , "Transmission Transfer Gear and Torque Converter Updates for 994 Wheel Loaders" 
SMHS8079  Reuse & Salvage Guidelines , "Installation of 6T-1995 Housing As And 6T-2483 Transfer Gear Case Assembly" 
SEBF9241  Reuse & Salvage Guidelines , "Inspection of Synchronizer Assemblies for Continuously Variable Transmissions" 
SEBF9324  Reuse & Salvage Guidelines , "Inspection of Clutch Reaction Splines in Aluminum Transmission Cases" 
SEHS9420  Reuse & Salvage Guidelines , "Output Transfer Shaft and Case Rework" 

For information concerning Planetary Final Drives, Non-Planetary Final Drives and/or gear failure, see the following Reuse and Salvage Guidelines.

Table 3
References Material 
Media Number  Publication Type & Title 
SEBF8078  Reuse & Salvage Guidelines , "Non-Planetary Final Drives (TTT)" 
SEBF8079  Reuse & Salvage Guidelines , "Planetary Final Drives for Track-Type Tractors" 
SEBF8084  Reuse & Salvage Guidelines , "Procedure to Repair Damaged Sprocket Hubs for D8L, D8N, D9L, D9N, D10N, and D11N Tractors" 
SEBF8093  Reuse & Salvage Guidelines , "Planetary Final Drives for Wheel Loaders, Wheel Tractors, Compactors, Underground Articulated Trucks" 
SEBF8132  Reuse & Salvage Guidelines , "Salvage of Final Drive Sprocket Hubs For Pipelayers, Track Loaders, and Track-Type Tractors" 
SEBF8135  Reuse & Salvage Guidelines , "Repair of Web Cracks In Final Drive Planetary Carriers" 
SEBF8168  Reuse & Salvage Guidelines , "Salvage of Final Drive Carrier Plate for Track-Type Loaders" 
SEBF8182  Reuse & Salvage Guidelines , "Salvage and Reuse of Final Drive Axle Bearings Used in Off-Highway Trucks/Tractors and 990, 992, and 994 Wheel Loaders" 
SEBF8183  Reuse & Salvage Guidelines , "Salvage of Final Drive and Differential Thrust Washer Used in Off-Highway Trucks, Tractors, and Wheel Loaders" 
SEBF8185  Reuse & Salvage Guidelines , "Salvage Procedure for Final Drive Planet Gear Used in Off-Highway Trucks" 
SEBF8221  Reuse & Salvage Guidelines , "Salvage of Planetary Carrier (Outer Pin Bore) Using Pressed In Sleeves for 785 and 789 Trucks" 
SEBF8222  Reuse & Salvage Guidelines , "Salvage of Planetary Carrier Pin Bores Using Tapered Roller Bearings for 785 and 789 Trucks" 
SEBF8223  Reuse & Salvage Guidelines , "Salvage of Inner Planetary Carrier Pin Bores using Tapered Roller Bearings for 785, 789, and 793 Off-Highway Trucks" 
SEBF8225  Reuse & Salvage Guidelines , "Reusability of Final Drive Splines on 785, 789, 793, and 797 Off-Highway Trucks" 
SEBF8285  Reuse & Salvage Guidelines , "Salvage of Outer Planetary Carrier Pin Bores, Using Metal Spray and Machining Operations for 793 Off-Highway Trucks" 
SEBF8419  Reuse & Salvage Guidelines , "Axle Housing and Final Drive Hub Salvage Procedure for 24H Motor Graders" 
SEBF8752  Reuse & Salvage Guidelines , "Off-Highway Truck Final Drive Planetary Carrier" 
SEBF8759  Reuse & Salvage Guidelines , "Reusability of Rear Final Drive Splines on 769 to 784 Off-Highway Trucks" 
SEBF8841  Reuse & Salvage Guidelines , "Planetary Final Drives for Small and Medium Wheel Loaders and Small Integrated Tool Carriers" 

Planet Carriers



Illustration 1g02297999
Planet carrier.

Planet Shaft Bores

Light fretting is acceptable, but a wear step that can be felt with a fingernail is not acceptable. If the wear step can be felt with a fingernail, do not use again

Planet Shaft Retention Ball Pocket

The bottom or sides of the pocket must not be worn more than 1.0 mm (0.04 inch). No cracks in the pocket are permitted. If the shaft retention ball pocket is worn more than 1.0 mm (0.04 inch), and/or has any cracks, do not use again.

Planet Gear Thrust Faces

A thrust face showing light circumferential scratches and/or small nicks can be used again after the scratches are removed and the thrust face is polished. Remove the nicks and scratches with a file and polish with 240 grit emery paper.

Spline Wear

Wear steps, up to 0.30 mm (0.012 inch) deep, per side, are acceptable on the splines. To measure wear, hold a straight edge against the unworn part of the spline (see Illustration 3). Use a feeler gauge, as shown in Illustration 3, to measure the gap between the straight edge and the worn surface. If the wear step exceeds 0.30 mm (0.012 inch), do not use again.



Illustration 2g02298093
Wear steps on splines.

Use again if wear steps do not exceed 0.30 mm (.012 inch).



Illustration 3g02298113
Top view of spline. Use a straight edge and feeler gauge to measure wear step on both sides of the spline.

Carrier Deck Cracks

Only 8S-0005 Carriers with deck cracks that meet the following criteria can be used again. Other carriers cannot be used again if any cracks are visible anywhere on the carrier deck. 8S-0005 Carriers with cracks visible on the outside edge of the decks, can be used again (see Illustration 4). If cracks are visible on the flat surface of the decks, do not use again (see Illustrations 5 and 6). use a penetrant or magnetic particle procedure to identify cracks.



Illustration 4g02298234
8S-0005 Carrier deck with crack visible only on edge.

Use again if cracks are not visible on the flat deck surfaces of an 8S-0005 Carrier.



Illustration 5g02298283
8S-0005 Carrier deck with crack on flat surface.

Do not use again if crack extends onto the flat surface.



Illustration 6g02298293
8S-0005 Carrier with crack extending onto flat surface.

Planet Shafts

Shaft Support Diameters

Wear steps on the diameters of the shaft support are not acceptable. If there are no wear steps, but only light fretting, the shaft may be used again. See Illustration 7.



Illustration 7g02298335
Shaft support diameter with light fretting.

Use again

Bearing Diameters

Pitting, spalling, or wear steps that can be felt with a fingernail are not acceptable. Light scratches may be acceptable, but only if scratches do not catch a piece of tag wire or paper passed across the top of the scratched surface.

Gears



Illustration 8g02298553
Gear nomenclature.

Nomenclature

Crown: Slight convex outline of a gear tooth viewed from the top (see Illustration 8). The slightly rounded shape of the tooth crown compensates for minor gear tooth misalignment by avoiding load concentration on the ends of the teeth.

Profile: Shape or outline of the tooth as seen from the side of the tooth.

HPSTC: Highest point of single tooth contact.

LPSTC: Lowest point of single tooth contact.

Pitch Line: The tooth location between the HPSTC and the LPSTC where there is no sliding action between the two mating gear teeth surfaces.

Rolling/Sliding Action: When two mating gears rotate, the teeth go through a combined rolling/sliding action (see Illustration 9).



Illustration 9g02298854
Rolling/Sliding action.

Rolling/Sliding Action

The rolling/sliding action takes place when two teeth begin to make contact. As the teeth engage, the sliding action stops at the operating pitch line. The rolling action continues until the tip of the drive gear tooth and the root of the driven gear begin to make contact. Currently, sliding/rolling action resumes and the cycle begins again (see Illustration 9).

Sliding action, plus the load placed between two teeth, is the basic operational cause of surface damage, such as scoring, on gear teeth. Sliding action is greatest near the tooth tip and root. These areas must be inspected for scoring and other types of surface damage.

Sliding under a high load can also cause pitting. The areas of greatest stress caused by sliding are the LPSTC of the sun gear and the HPSTC of the planet and ring gears. These areas need careful inspection for pitting.

Pitting And Spalling

Pitting is a type of surface or subsurface fatigue failure of a gear tooth. Pitting is usually the result of high contact stresses and the rolling/sliding action of two gear teeth. A pit begins as a minute crack, less the 0.13 mm (0.005 inch) deep, which causes a small amount of metal to separate from the surface of the gear tooth. This separation then appears as a pit. There are two types of pitting: initial and destructive.

Destructive pitting usually occurs after a long period of operation and high contact stresses. Inadequate lubrication can also cause destructive pitting. Destructive pitting can progress rapidly into either spalling, or complete disintegration of the tooth. Each pit acts as a point of stress concentration which accelerates pit formation until the tooth fractures.

Pitting, if not corrected, can progress into spalling (see the section on "Spalling" for additional information).

Initial Pitting

If ridges or high spots are present in high load areas, surface cracks and surface pits may begin to develop. Such pits are less than 0.7 mm (.03 inch) in diameter and tend to distribute the load by progressively removing the high contact areas. When the load is more evenly distributed, pitting slows, and the surface begins to polish. This pitting is called "initial pitting: or "Corrective Pitting". Illustrations 11 through 19 show initial pitting.



Illustration 10g02300833
Initial pitting


Illustration 11g02300893
Magnified view of initial pitting on gear tooth.


Illustration 12g02300933
Initial pitting in the fillet section of the tooth. Pitting is localized into one area.


Illustration 13g02300975
Magnification of Illustration 12.


Illustration 14g02300993
Initial pitting in the fillet section on a different tooth of the same gear. Again, pitting is localized into one area.


Illustration 15g02306753
Magnification of Illustration 14.


Illustration 16g02306754
Initial pitting with larger single pits covering more of the tooth face.


Illustration 17g02308376
Magnification of Illustration 16.


Illustration 18g02308415
Initial pitting with larger single pits covering more of the tooth face and extending into the root of the gear.


Illustration 19g02308553
Magnification of Illustration 18.

Note: Illustrations 10,12,14,16, and 18 Use again after lightly polishing the tooth profiles with a 6V-2010 Stone and oil.

Destructive Pitting

Destructive pitting usually occurs after a long period of operation and high contact stresses. Inadequate lubrication can also cause destructive pitting. Destructive pitting can progress rapidly into either spalling or complete disintegration of the tooth. Each pit acts as a point of stress which accelerates pit formation until the tooth fractures. Illustrations 20 through 26 show the progression of a typical gear tooth failure from destructive pitting through spalling.



Illustration 20g02308581
Early stage of destructive pitting.


Illustration 21g02308595
Early stage of destructive pitting (magnification x 20).


Illustration 22g02308635
Cross sectional view of destructive pitting (magnification x 100).


Illustration 23g02308665
Stage two of destructive pitting. Damage has progressed across the tooth.


Illustration 24g02308713
Stage three of destructive pitting. Damage has progressed vertically on the tooth face.


Illustration 25g02308793
Stage four of destructive pitting. Damage has progressed from pitting to spalling.


Illustration 26g02308844
Cross section view of a gear tooth showing pitting damage which has progressed to spalling.


Illustration 27g02308860
Early stage destructive pitting

Do not use again sun and planet gears. Use again ring gears.



Illustration 28g02308874
Appearance of pitting. What appears to be pits are really machining marks. A dark appearance on the edges of the teeth and in the machining marks is caused by the extreme pressure gear oil used in the final drive.

Use again



Illustration 29g02317350
Early stage of destructive pitting.


Illustration 30g02317373
Moderate pitting.

Illustrations 29 & 30 Do not use again sun and planet gears. Use again ring gears.



Illustration 31g02319393
Start of destructive pitting in the ring gear.


Illustration 32g02319413
Pitting between the pitch line and fillet.


Illustration 33g02319433
Magnified photo of pitting shown in Illustration 32.

Illustrations 31 & 32 Do not use again.



Illustration 34g02319435
Advanced stage of destructive pitting.


Illustration 35g02335079
Crack in tooth initiated from destructive pitting.

Illustrations 34 & 35 Do not use again.

Spalling

Spalling is a type of subsurface fatigue failure. Spalling usually begins with a small fatigue crack under the surface of the gear tooth. The tooth surface is then weakened and metal flakes away from the tooth face. Once spalling begins, the damage can progress quickly to gear tooth fracture.

Note: Note: While spalling is often the final stage of pitting, each can occur separately.

Abrasive Wear

Abrasive wear on gear teeth is caused by small foreign particles, such as dirt or metal, in the lubrication system. These small particles act as a lapping compound during machine operation and wear down the gear tooth surface.

During the early stage of abrasive wear, the gear teeth will have a satiny, not shiny, appearance. The next stage of abrasive wear results in the appearance of flat spots on the gear tooth profile and a reduction of the tooth crown. The advanced stage of abrasive wear results in deep grooves appearing on both sides of the gear tooth pitch line. Abrasive wear of the gear teeth is accompanied by wear on all transmission components, including bearing needles, cages, and races.

Note: If abrasive wear is found in the gear train, correct the source of contamination.



Illustration 36g02336036
Advanced abrasive wear around the gear tooth pitch line. Notice that the tooth profile is altered because of the advanced wear.

Gear Cleaning and Inspection

Note: Gears must be cleaned prior to inspection. After removing the gears from the transmission, clean and ensure that all are free of dirt, water, and oil. If the gears are to be stored after inspection, coat with a thin layer of oil and store in a clean, dry place.

After cleaning the gear, carefully inspect every tooth completely for cracks, pitting, spalling, or any surface damage. This inspection may be accomplished using a magnifying glass and a strong light source (sunlight is best). It may be difficult to distinguish between small scratches and cracks. Magnetic particle, or dye penetrant may be also used to ensure that the gear is reusable.


NOTICE

It is important to inspect every tooth of each gear. It is possible for only one tooth to be damaged. If a gear is used again after falling within the "Do not use again" criteria, failure may result in damage to other transmission components.


Planet Gears

Teeth

Some planet gears may have wear or damage on only one side (face) of the teeth. Do not turn the gears around to present new wear surface if the gear does not meet "Use again" criteria. Planet gears are idler gears. During each revolution there is equal tooth loading in both directions on every tooth. This tooth loading causes a planet gear to be unusable if wear or damage on only one side (face) of the teeth meets the "Do not use again" criteria.

Cracks

No cracks or any amount of pitting and/or spalling are acceptable on planet gear teeth. If any evidence of cracks, pitting or spalling is visible, do not use again.

Note: What appear to be small cracks may only be hob (gear cutter) marks. Inspect the gear carefully using Illustrations 37 and 38 for reference.

It is common for shaving marks or machining marks to polish away without development of surface pits. Load carrying surfaces may become polished until they are mirror-like as seen in Illustration 39.



Illustration 37g02336137
Machining marks may appear to be cracks.


Illustration 38g02336180
What appears to be several cracks on the planet gear tooth are actually hob marks.

Illustrations 37 and 38 Use again.

Frosting



Illustration 39g02336196
Surfaces of planet gear teeth have become frosted. Small pits are forming in the frosted area.

Do not use again.

Frosting can also appear as thin surface layers of the tooth missing in bigger areas. This condition occurs when a rough surface or tiny projections from the surface make contact and microweld. The surface metal then either pulls out or fractures on a small scale. This results in a gray matte appearance which is not detrimental at this stage. However, if the conditions causing "frosting" are not corrected, destructive pitting may begin. See Illustration 40.



Illustration 40g02336220
Frosting. If pitting has started, do not use the gear again.

Use again after correcting the condition that caused the "frosting". Do not use again if pitting has started.

Surface Blemishes



Illustration 41g02336264
Planet gear tooth edge with a small nick.

Use again only after removing the nick with a 6V-2010 Polishing Stone.



Illustration 42g02336273
Planet gear tooth surface shows an indentation.

Do not use again.

Surface blemishes, resulting from foreign material, are acceptable only if the material did not cause indentations on the faces of planet gear teeth.

Planet gear teeth with small nicks may be reusable, but only if the nick can be removed with a 6V-2010 Polishing Stone.

Indentations can result in case cracking and can result in tooth failure and result in damage to the transmission components.

Excessive Wear

Excessive wear can cause an increased noise level and accelerates the tendency for tooth surface pitting and spalling.

To test for excessive wear on planet gears, except those that are listed below, place a straight edge across a gear tooth. If there is not excessive wear, the straight edge can be rocked against the tooth crown as shown in Illustration 43. Do not use gears that show excessive wear.

Note: The amount of crown is small, only 0.020 to 0.150 mm (0.0008 to 0.0059 inch). Most measurements fall into the 0.025 to 0.030 mm (0.0010 to 0.0012 inch) range. Therefore, the amount of rocking will be slight.

The following gears do not have crowned teeth.

Table 4
Chart A
Gears Without Crowned Teeth 
7G-2491  7G-2497  7G-2500 
7G-2502  7G-2504  7G-2508 
7G-2524  7G-2525  7G-3459 


Illustration 43g02336399
Place a straight edge along the pitch line of a crowned gear tooth. If the straight edge can be rocked, the amount of wear if NOT excessive.

Planet Gear Bearing Bore

Excessive Wear

Bearing bores with excessive wear will not adequately guide the bearing cage and could result in premature bearing failure.

The length of the bearing needles is not precisely controlled. If a bearing with long needles is installed in a gear with a wear step created by shorter needles, this could result in premature bearing failure.

To determine the amount of wear on the bearing bore, use a dial bore gauge to measure both a portion of the bore showing the most wear, and an unworn portion of the bore. Subtract the two measurements. No more than 0.013 mm (0.0005 inch) is permitted.

Note: Note: Gears with bore wear exceeding the maximum amount permitted may be sectioned and used as a guide to compare with wear on other gears.

Use the following illustrations as aids to determine whether planet gear bearing bores fall within the "Do not use again" criteria.



Illustration 44g02336636
Shallow pits have developed in the bearing bore due to rust and foreign material.


Illustration 45g02343057
Pitting in the bearing bore has progressed to spalling.

Illustrations 44 & 45- Do not use again.



Illustration 46g02343116
Excessive wear in the bearing path caused by cage contact with the bore.


Illustration 47g02343136
Severe wear to bearing bore caused by bearing cage. Wear will not allow the bearing bore to guide a new bearing correctly and will cause premature failure.

Illustrations 46 & 47 Do not use again.

Rust

Gears with light rust on the bearing bore can be used again if the rust can be removed by light polishing with crocus cloth and oil. Gears showing heavy rust cannot be used again because the rust will create pits.



Illustration 48g02343161
Water inside the transmission caused excessive rust on the planet gear bearing bore.

Do not use again.

Foreign Material

Foreign material, usually the result of another failure, can result in bearing bore indentations and pitting. Dents in the bearing bore can greatly reduce the bearing contact area and/or create cracks in the surface, resulting in substantially shortened bearing life.



Illustration 49g02343197
Excessive amount of damage to the planet gear bearing bore due to foreign material.

Thrust Faces

Scratches

Light, circumferential scratches may be acceptable, but only if they do not catch a piece of tag wire or paper passed across the top of the scratched surface. Use a 6V-2010 Polishing Stone to remove any radial scratches or small nicks.

Wear

Gears with more than 0.03 mm (0.001 inch) thrust face wear cannot be used again. To measure the amount of wear, place the gear on a surface plate. Measure the wear step with a dial indicator at several locations across the worn area, following the wear path from the inside to the outside. Wear must be even across the wear path.



Illustration 50g02343236
Planet gear thrust face.

Do not use again if face wear exceeds 0.03 mm (0.001 inch).

Planet Gear Thrust Washers

Newer, green, dark gray/black, or light brown thrust washers can be used again if they are not chipped, cracked, burned, melted, grooved, or worn. Do not reuse the older, tan color washers.

Sun Gears

No pitting, spalling, or cracks are acceptable.

Frosting is a condition caused by inadequate oil film between mating gear teeth surfaces. It appears as a cloudy area on the gear contact surface and is sometimes accompanied by small surface pits.

Gears with frosting can be used again provided any surface pits are small enough that they do not catch a piece of tag wire passed along the frosted surface. Frosting accompanied by any pit that does catch a tag wire is unacceptable and the gear should not be used again.

Frosting is different in appearance than abrasive wear or light surface rust. Abrasive wear, due to foreign material, usually covers the entire tooth face contact surface and has a more satiny, shiny appearance.

Abrasive wear will usually appear on all gears and other transmission components. Light surface rust or corrosion can produce a mottled appearance, which has an irregular outline.

Note: If abrasive wear is found in the gear train, correct the source of contamination. Light surface rust or corrosion can produce a frosted appearance, but usually is of irregular shape. Gears with this type of condition can be reused if there are no pits or other defects.



Illustration 51g02343296
Surfaces of the sun gear teeth have become frosted and small pits have formed in the frosted area.

Do not use again.

Ring Gears

Reusability of ring gears depends on the amount of damage or wear. Some damaged clutch ring gears obviously cannot be used again. Other gears, with certain limitations, can be used again. Some clutch ring gears can be reused without limitations, depending upon the location and degree of damage.

Common types of damage which do not necessarily effect on reuse are:

  • Wear of the ring gear side face

  • Wear on crown of outer teeth

  • Notches on face of outer teeth

  • Damage caused by debris

for complete information concerning the reusability of ring gears, see Reuse and Salvage Guidelines, SEBF8017, "Clutch Ring Gears for All Power Shift Transmissions".

Main Shafts

For complete information concerning the reusability of main shafts, see Reuse and Salvage Guidelines, SEBF8060, "Repair of Transmission, Torque Converter, and Torque Divider Shafts".

Bearings

Reuse bearings with less than 2,000 hours of use if there is no visible damage caused by other failures.

Do not use bearings showing any cage wear or discoloration.

Clutch Friction Material

For complete information concerning the reusability of main shafts, see Reuse and Salvage Guidelines, SEBF8013, "Transmission Clutch Plates and Disc Assemblies with Sintered Bronze Friction Material", Reuse and Salvage Guidelines, SEBF8031, "Transmission Clutch Plates and Disc Assemblies with F37 Clutch Friction Material", and Reuse and Salvage Guidelines, SEBF8098, "Transmission Clutch Plates and Disc Assemblies with RAYFLEX® Friction Material".

Clutch Pistons and Housings

Ensure that there are no burrs, nicks, or scratches on housing faces that form a metal-to-metal oil seal. See Reuse and Salvage Guidelines, SEBF8006, "Clutch Housings and Clutch Pistons for Transmissions and Torque Dividers (with Cast Iron Seal Rings)" and Reuse and Salvage Guidelines, SEBF8014, "Identification and Applications of Transmission Clutch Plates and Specifications to Machine Reaction Faces for Power Shift Transmissions" for additional salvage information.

Selector and Pressure Control Valves

No scratches, nicks, or dents are acceptable on valve spools. If spools appear to have a satiny surface, it is an indication of abrasive wear.

Check spool and bore for excessive wear, such as spalling, pitting, and cracking. If excessive wear is present, do not use again. No scratches are acceptable in the bores. The metering edges of spools and bodies must be sharp and not rounded by erosion.

Springs

No rust or pitting are acceptable on valve springs. Check free length of valve spring and loaded length. Refer to the appropriate Service manual for specifications.

Cases

Check for cracks and blocked oil passages. Check pilot diameters and mounting faces for excessive wear or fretting. Check dowel pin bores for wear and cracks. If any of the above conditions are found, do not use again.

Caterpillar Information System:

CX28 Transmission For Combat and Tactical Vehicles Transmission & Transfer Case Electronic Control System Transmission, SPN 191 - FMI 8
CX28 Transmission For Combat and Tactical Vehicles Transmission & Transfer Case Electronic Control System Transmission, SPN 191 - FMI 14
CX28 Transmission For Combat and Tactical Vehicles Transmission & Transfer Case Electronic Control System Transmission, SPN 190 - FMI 8
CX28 Transmission For Combat and Tactical Vehicles Transmission & Transfer Case Electronic Control System Transmission, SPN 177 - FMI 4
CX28 Transmission For Combat and Tactical Vehicles Transmission & Transfer Case Electronic Control System Transmission, SPN 177 - FMI 3
CX28 Transmission For Combat and Tactical Vehicles Transmission & Transfer Case Electronic Control System Transmission, SPN 177 - FMI 16
CX28 Transmission For Combat and Tactical Vehicles Transmission & Transfer Case Electronic Control System Transmission, SPN 1751 - FMI 19
CX28 Transmission For Combat and Tactical Vehicles Transmission & Transfer Case Electronic Control System Transmission, SPN 168 - FMI 4
CX28 Transmission For Combat and Tactical Vehicles Transmission & Transfer Case Electronic Control System Transmission, SPN 168 - FMI 3
CX28 Transmission For Combat and Tactical Vehicles Transmission & Transfer Case Electronic Control System Transmission, SPN 161 - FMI 8
CX28 Transmission For Combat and Tactical Vehicles Transmission & Transfer Case Electronic Control System Transmission, SPN 158 - FMI 2
CX28 Transmission For Combat and Tactical Vehicles Transmission & Transfer Case Electronic Control System Transmission, SPN 126 - FMI 3
CX28 Transmission For Combat and Tactical Vehicles Transmission & Transfer Case Electronic Control System Transmission, SPN 3027 - FMI 3
CX28 Transmission For Combat and Tactical Vehicles Transmission & Transfer Case Electronic Control System Transmission, SPN 3027 - FMI 4
CX28 Transmission For Combat and Tactical Vehicles Transmission & Transfer Case Electronic Control System Transmission, SPN 3463 - FMI 2
CX28 Transmission For Combat and Tactical Vehicles Transmission & Transfer Case Electronic Control System Transmission, SPN 3509 - FMI 3
CX28 Transmission For Combat and Tactical Vehicles Transmission & Transfer Case Electronic Control System Transmission, SPN 3509 - FMI 4
CX28 Transmission For Combat and Tactical Vehicles Transmission & Transfer Case Electronic Control System Transmission, SPN 3823 - FMI 16
CX28 Transmission For Combat and Tactical Vehicles Transmission & Transfer Case Electronic Control System Transmission, SPN 3823 - FMI 3
CX28 Transmission For Combat and Tactical Vehicles Transmission & Transfer Case Electronic Control System Transmission, SPN 3823 - FMI 4
CX28 Transmission For Combat and Tactical Vehicles Transmission & Transfer Case Electronic Control System Transmission Shifting Function
CX28 Transmission For Combat and Tactical Vehicles Transmission & Transfer Case Electronic Control System System Protection Functions
CX28 Transmission For Combat and Tactical Vehicles Transmission & Transfer Case Electronic Control System Additional Functions
CX28 Transmission For Combat and Tactical Vehicles Transmission & Transfer Case Electronic Control System Transmission, SPN 3825 - FMI 8
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