Salvage of Transmission Transfer Gear Case and Cover for Articulated Trucks, Compactors, Load Haul Dump, Wheel Loaders, Wheel Tractors, and Motor Graders {0679, 3075, 3159} 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

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.

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 transmission transfer gear case and cover. 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.

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.

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 transmission transfer gear case and cover 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.

Bearing Failure

Illustration 6	g03651611
Semi-finished replacement cover

When a bearing failure has occurred in the transfer gear case, the cover, as shown in Illustration 6, is sometimes damaged.

A bearing failure usually allows the gears to move into the cover damaging the inner face of the cover. Normally, damage to the inner face is not repairable and renders the cover unusable. The original case assembly covers are not serviced separately due to the close tolerances of the bore alignment from the case to the cover. This means that a semi-finished cover must replace the original case assembly cover. Refer to Table 4 for a summary of the original case assembly covers and the replacement covers.

A new, semi-finished cover is available which can be used for salvaging the damaged transfer case assembly. This guideline provides the step-by-step instructions to assemble a semi-finished cover onto the original case. The case assembly is then aligned and bolted to boring machine where the bores in the cover are machined to the correct diameters. Finally, dowel holes are machined. The oversized dowel pin can be purchased through the AVSpare Parts Distribution System. Once the machining is complete, the transfer case can be assembled and placed back into service.

Transmission Transfer Gear Case Part Number Summary

Salvage Procedure

Note: The machining process presented in this guideline may be completed using set-up methods other than the procedures depicted herein. The transfer gear case and cover may be secured to the machine center in various ways. Use of alternative set-up configurations and machining processes are acceptable.

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Illustration 7	g03651615
Locate the case on one side with cover facing the spindle.

1. Support the transfer gear case in a horizontal position. Carefully bolt the new, semi-finished cover to the case using a minimum of eight (8) bolts. The cover should be positioned so the bolts are centered in the bolt holes and then tightened. Refer to Table 4 to identify the appropriate replacement cover.
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   Illustration 8	g03651619
   Initial parallel and perpendicular alignment of case to spindle.

2. Position the case so the cover is facing the spindle. Refer to Illustration 7.
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   Illustration 9	g03651650
   Place two dial indicators on the upper face of the cover at the locations shown by the arrows.

3. Secure the case onto the table using the clamping kit . Tighten the clamps until the clamps are hand tight. Using a dial indicator , sweep the machined face of the cover to align it parallel and perpendicular to the spindle within 0.13 mm (0.00512 inch) total indicator run-out (TIR). Refer to Illustration 8.
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   Illustration 10	g03651656
   Place two indicators on the lower face of the cover at the locations shown by the arrows.

4. Position four dial indicators on the face of the cover. Place two on the upper surface and two on the lower surface as shown in Illustrations 9 and 10. Zero the indicators. Tighten the hold-down clamps evenly. Use the dial indicators to ensure that the case does not twist.
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   Illustration 11	g03651659
   Nomenclature for bores in the cases and covers. (1) Right-hand bore (cover) (2) Center bore (cover) (3) Left-hand bore (cover) (4) Left-hand bore (case) (5) Center bore (case) (6) Right-hand bore (case) (7) Case (8) Cover

5. Mount a small indicator into the spindle, and move it approximately to the center of right-hand bore (1) in the cover. Refer to Illustration 12 for the location of the indicator.
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   Illustration 12	g03651668

6. Move the indicator into bore (6) in the case, and align it with the spindle to within 0.013 mm (0.0005 inch) TIR. Refer to Illustration 13. Lock both the horizontal and vertical axes of the boring machine to ensure that the spindle location does not move.

   Note: Care must be taken to ensure that the case does not move during Step 7. Place the indicators on the other surfaces of the case to check for movement. The cover may require more alignment.

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   Illustration 13	g03651676
   Center (zero) the large (right-hand) bore in the cover with the spindle.

7. Retract the spindle of the boring machine and mount a large dial indicator in the spindle. Position the indicator on the inside diameter (ID) of the right-hand bore in the cover as shown in Illustration 13. Center (zero) the bore to within 0.13 mm (0.0051 inch) TIR.
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   Illustration 14	g03651686
   Locate the dial indicator for alignment of bore (4) in the case.

8. Remove the large indicator, and move the spindle to left-hand bore (3) in the cover. Refer to Illustration 14 for the location.
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   Illustration 15	g03651716
   Center (zero) left-hand bore in the case with the spindle.

9. Mount the small indicator into the spindle and center (zero) the bore in the case to the spindle within 0.013 mm (0.0005 inch) TIR. Lock both horizontal and vertical axes. Refer to Illustration 15.
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   Illustration 16	g03651720
   Center (zero) the left-hand bore in the cover.

   Note: Care must be taken to ensure that the case does not move during Step 10. The cover may require more alignment. To assure the case does not move, indicators can be positioned against the case to check movement.

   Note: Care must also be taken to ensure that the right-hand bore in the cover is still in alignment. To check for movement mount two dial indicators in the ID of the right-hand bore, locate one dial indicator at 0° and one dial indicator at 90 degrees. Set both dials to zero. This will allow the operator to maintain the original alignment of the right-hand bore while repositioning the left-hand bore.

10. Retract the spindle of the boring machine and mount a large dial indicator . Position the indicator in the ID of the left-hand bore as shown in Illustration 16. Center (zero) the bore to within 0.13 mm (0.0051 inch) TIR. Tighten the bolts to standard torque to prevent movement during the machining process.
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    Illustration 17	g03142058
    Machine the left-hand bore in the cover.

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    Illustration 18	g03651723
    Cover

11. Remove the dial indicator and mount the boring bar into the spindle. Perform the semi-finish, finish, and chamfer operations for the left-hand bore as shown in Illustration 17. The surface finish of the bore and the chamfer is an "H" finish. Use Tooling H to evaluate the surface finish. Refer to Table 5 for the bore dimensions.
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    Table 5

    Machining Dimensions Summary
    Location	Diameter	Chamfer	Angle	Finish
    1	223.82 ± 0.05 mm (8.81179 ± 0.00197 inch)	0.8 ± 0.2 mm (0.03150 ± 0.00787 inch)	30°	H
    2	336.55 ± 0.05 mm (13.24997 ± 0.00197 inch)	1.5 ± 0.5 mm (0.05906 ± 0.01969 inch)	30°	F
    3	192.51 ± 0.05 mm (7.57912 ± 0.00197 inch)	1.5 ± 0.5 mm (0.05906 ± 0.01969 inch)	30°	F

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    Illustration 19	g03142132
    Center (zero) the right-hand bore in the case.

12. Refer to Illustration 11 for bore locations and nomenclature. Move the spindle to the right-hand bore (1) and align bore (6) in the case to within 0.013 mm (0.0005 inch) TIR as shown in Illustration 19. Lock both the horizontal and vertical axes of the boring machine to ensure that the spindle location does not move.
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    Illustration 20	g03142138
    Machine right-hand bore (1) in the cover.

13. Remove the dial indicator and mount the boring bar into the spindle. Perform the semi-finish, and chamfer operations for right hand bore (1) in the cover as shown in Illustration 20. The surface finish for the bore and chamfer must be an "F" finish. Use surface texture comparison tool to evaluate the surface finish.
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    Illustration 21	g03142140
    Center (zero) bore (5) in the case.

14. Move the spindle to center bore (2) of the cover. Mount the small dial indicator into the spindle and center (zero) bore (5) in the case to within 0.013 mm (0.0005 inch) TIR as shown in Illustration 21. Lock both the horizontal and vertical axes to ensure that the spindle does not move.
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    Illustration 22	g03142142
    Machine center bore (2) in the cover.

15. Remove the indicator and mount the boring bar into the spindle. Perform the semi-finish, finish, and chamfer operations for center bore (2) as shown in Illustration 22. The surface finish of the bore and chamfer should be machined to an "F" finish. Use surface texture comparison tool to evaluate the surface finish.
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    Illustration 23	g03142145
    Center (zero) one of the dowel holes in the case.

16. After all three bores in the cover are machined, mount a dial indicator into the spindle. Center (zero) one of the existing finished dowel holes in the case to within 0.013 mm (0.00051 inch) TIR as shown in Illustration 23. Lock the horizontal and vertical axes of the machine. Remove the dial indicator.

    Note: The hole in the semi-finished cover is smaller than the hole in the case. Therefore, accurately determining TIR in Step 16 may be difficult. Make sure that the TIR is within 0.013 mm (0.0005 inch).

    Note: Place a dial indicator against the rear face of the case to check for movement during machining or installation of the dowel. If the case should move, it may allow the misalignment of the case and cover bores, which may cause the failure of the transfer case.

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    Illustration 24	g03142150
    Drilling the dowel hole in the cover.

17. Enlarge the semi-finished dowel hole with a 19.0 mm (0.7480 inch) drill bit as shown in Illustration 24. Drill through the cover and to the depth of the existing dowel hole in the case.
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    Illustration 25	g03142156
    Reaming the dowel hole in the cover.

18. Use Tooling C to ream the dowel hole to the finished diameter of 20.638 ± 0.015 mm (0.8125 ± 0.0006 inch) as shown in Illustration 25. Ream through the cover to the depth in the case. After machining, clean all debris from the dowel hole.

19. To install the second dowel, repeat Steps 17 and 18.

20. Remove the case assembly from the table of the boring machine. Wash and thoroughly clean all metal chips and debris from the case. Assemble the reconditioned transfer gear case according to the appropriate Disassembly and Assembly Manual.