NMWR_9-2520-585__Differentials_June_2010.pdf

NMWR 9-28155--227744

*NMWR 9-2520-585

NATIONAL MAINTENANCE WORK REQUIREMENTS

CONTAINING NATIONAL OVERHAUL STANDARDS

FOR

FRONT AND REAR DIFFERENTIALS

HMMWV FOV

NSN 2520-01-291-2975, P/N 12338415-3

NSN 2520-01-358-3160, P/N 12342615

NSN 2520-01-416-5217, P/N RCSK17305

NSN 2520-01-498-9104, P/N 12469309

AVAILABILITY STATEMENT: This publication is not available through the AG publication centers. This publication is available through U. S. Army TACOM Life Cycle Management Command, Warren, MI 48397-5000.

DISTRIBUTION STATEMENT A: Approved for public release; distribution is unlimited.

*Supersedes NMWR 9-2520-585, 19 October 2007.

U.S. ARMY TACOM LIFE CYCLE MANAGEMENT COMMAND

June 2010

NMWR 9-2520-585

WARNING SUMMARY

This warning summary contains general safety warnings and hazardous materials warnings that must be understood and applied during operation and maintenance of this equipment. Failure to comply may result in serious injury or death to personnel.

Improper cleaning methods and use of unauthorized cleaning solutions may result in injury to personnel and/or damage to equipment.

Compressed air used for cleaning purposes must not exceed 30 psi (207 kPa). Use only with effective chip guarding and personal protective equipment (goggles/shield, gloves, etc.).

Do not use compressed air to dry bearings.

Direct all personnel to stand clear during hoisting operations. A heavy swinging load can be extremely dangerous.

When steam cleaning, protective clothing must be used.

Degreasing solvent is flammable and must not be used near an open flame. A fire extinguisher must be kept nearby when solvent is used. Use only in well-ventilated places.

Use extreme care when handling heavy parts. Provide adequate support and use assistance during procedure.

Wear adequate protective goggles/shields to prevent injury from possible airborne fragments.

a/b blank

LIST OF EFFECTIVE PAGES/WORK PACKAGES

The date of issue for original pages/work packages for the NMWR is:

Original . . . . . . . . 01 June 2010

TOTAL NUMBER OF WORK PACKAGES IS 16

THE PAGES/WORK PACKAGES CONSISTS OF THE FOLLOWING:

Page No

Warning a

Warning b blank

A

B blank i ii blank iii iv blank v vi vii viii blank

WP 0001 00 – 0016 00 ... 0

*Zero in this column indicates original page.

A/B blank

*NMWR 9-2520-585

Headquarters, U.S. Army TACOM Life Cycle Management Command

Warren, MI, 01 June 2010

NATIONAL MAINTENANCE WORK REQUIREMENTS

CONTAINING NATIONAL OVERHAUL STANDARDS

REPORTING ERRORS AND RECOMMENDING IMPROVEMENTS

You can help improve this publication. If you find any errors, or if you would like to recommend any improvements to the procedures in this publication, please let us know. The preferred method is to submit your DA Form 2028 (Recommended Changes to Publications and Blank Forms) through the Internet, on the Army Electronic Product Support (AEPS) website. The Internet address is https://aeps.ria.army.mil. The DA Form 2028 is located under the Public Applications section in the AEPS Public Home Page. Fill out the form and click on SUBMIT. Using this form on AEPS will enable us to respond more quickly to your com-ments and better manage the DA Form 2028 program. You may also mail, email, or fax your comments or DA Form 2028 directly to U.S. Army TACOM Life Cycle Management Command, ATTN: AMSTA-LCL-MPP/ TECH PUBS, 1 Rock Island Arsenal, Rock Island, IL 61299-7630. The email address is tacomlcmc.daform 2028@us.army.mil. The fax number is DSN 793-0726 or Commercial (309)782-0726.

DISTRIBUTION STATEMENT A: Approved for public release; distribution is unlimited.

* Supersedes NMWR 9-2520-585, 19 October 2007.

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NMWR 9-2520-581

TABLE OF CONTENTS

Work Package/Page No.

How to Use This National Maintenance Work Requirement (NMWR) ....................................................................................... v

CHAPTER 1 GENERAL INFORMATION

List of Acronyms and Abbreviations .................................................. WP 0001 00 General Information .......................................................................... WP 0002 00

CHAPTER 2 MAINTENANCE INSTRUCTIONS

Disassembly ...................................................................................... WP 0003 00 Cleaning and Inspection ................................................................... WP 0004 00 Assembly .......................................................................................... WP 0005 00

CHAPTER 3 SUPPLEMENTAL INFORMATION

Supporting Instructions ..................................................................... WP 0006 00 After Repair Differential Performance Specifications and Test ......... WP 0007 00 After Repair Performance Test Report ............................................. WP 0008 00 Special Packaging Instructions ......................................................... WP 0009 00 Torque Limits .................................................................................... WP 0010 00 Tools and Special Tools List ............................................................. WP 0011 00 Mandatory Replacement Parts List ................................................... WP 0012 00 Expendable and Durable Items List .................................................. WP 0013 00 Repair Parts Introduction .................................................................. WP 0014 00 Repair Parts ...................................................................................... WP 0015 00

References ........................................................................................ WP 0016 00

Index ................................................................................................. Index 1 iii/iv blank

HOW TO USE THIS NATIONAL MAINTENANCE WORK REQUIREMENT (NMWR)

INTRODUCTION

This section explains the basic organization, contents, format, and special features of this NMWR. After reading this section, spend some time reviewing the NMWR to familiarize yourself with the contents and layout. This will enable you to locate information easily and reduce the time needed to complete required procedures.

ORGANIZATION AND CONTENTS

This NMWR is divided into three main chapters. Chapter 1 presents general information;

Chapter 2 presents maintenance instructions; and Chapter 3 supplemental information.

Chapter 1

List of acronym/abbreviations used throughout this NMWR and general information.

Chapter 2

Disassembly; cleaning and inspection; and assembly.

Chapter 3

Supporting instructions; after repair differential performance specifications and test; after repair performance test report; special packaging instructions; torque limits; tools and special tools list; mandatory replacement parts list; expendable and durable items list; repair parts introduction; and repair parts.

You can locate specific information in the NMWR by using either the Table of Contents located at the front of the NMWR or the alphabetical subject index located at the back of the NMWR.

v

HOW TO USE THIS NATIONAL MAINTENANCE WORK REQUIREMENT (NMWR) (Cont’d)

FORMAT

Work Package (WP) Format

Each chapter in this NMWR is divided into WPs that group data into stand-alone informational or task-oriented units. As shown in the table, Chapter 1 contains informational WPs while Chapter 2 contains primarily task-oriented WPs (maintenance procedures) followed by supplementary information WPs in Chapter 3.

Here are some important things to know about the WP format:

Each WP has its own identification number, which appears in the upper right corner of each page. WPs are numbered sequentially throughout the manual.

Each WP starts with page number 1. Page numbers appear at the bottom of the pages following the WP number.

Informational WPs begin with a listing of the specific topics covered in the order in which they appear in the WP. This listing provides you with a quick overview of each WP and enables you to locate specific information easily.

WP may identify the following information: tools, replacement parts, and other materials needed to complete the procedure in the WP. Before beginning a procedure, review the Initial Setup information to ensure all requirements have been met.

The task-oriented WPs (maintenance procedures) appear in the manual in the order of logical work sequence. This format makes the NMWR easy to follow and helps improve efficiency as you progress through the procedures.

Text and Illustration Modular Layout

Throughout this NMWR, WPs are set up in two-page modular layouts. This means that illustrations appear either on the same page as or on the page facing the step you are performing. This feature eliminates the need to search for illustrations that correlate with each procedural step.

In addition, procedural text is cross-referenced to numerical callouts in the illustrations, helping you immediately identify and locate specific parts mentioned. Figure and callout numbers referencing the illustrations appear in parenthesis in the text.

vi

HOW TO USE THIS NATIONAL MAINTENANCE WORK REQUIREMENT (NMWR) (Cont’d)

SPECIAL FEATURES

Illustration Features

This NMWR utilizes a variety of illustration methods such as locator views and exploded views to help you locate and identify parts easily. Each illustration is identified by a figure number and title printed below it.

The illustrations contain numerical callouts to identify parts, components, etc. mentioned in the text. Numerical callouts generally appear in clockwise order in the illustrations beginning at the 11 o’clock position.

A special feature of this NMWR is that the callout numbers for mandatory replacement parts are circled in the illustrations. This visually distinguishes mandatory replacement parts from those that may be repairable or otherwise reusable.

Each WP begins with Figure 1.

Supplemental Information

The WPs at the end of this NMWR contain supplemental information that supports the procedures in the NMWR. This information is cross-referenced in the Initial Setup list of each overhaul WP. The following supplemental information is included in this NMWR:

Torque Limits – Torque specifications for all fasteners used to assemble the component being overhauled in this NMWR.

Tools and Special Tools – Name, P/N, and NSN for common and special tools required for the procedures in this NMWR.

Mandatory Replacement Parts – Nomenclature, P/N, and NSN for all parts that must be replaced during overall of the component; may include cross-references to figure and item numbers in the Repair Parts WP.

Expendable and Durable Items – National Stock Number (NSN), description, Commercial and Government Entity Code (CAGEC), Part Number (P/N), and description for all expendable and durable items necessary to operate or maintain the equipment used in this NMWR.

Repair Parts and Special Tools List – Item number, Source, Maintenance, and Recoverability (SMR) code; NSN; CAGEC; part number; description and usable on codes

(UOC); and quantity for all parts required for the procedures in this NMWR.

References – All publications referenced in this NMWR.

vii/viii blank

CHAPTER 1

GENERAL INFORMATION

NMWR 9-2520-585 0001 00

LIST OF ACRONYMS/ABBREVIATIONS

THIS WORK PACKAGE (WP) COVERS:

Scope and List of Acronyms and Abbreviations

SCOPE

This Work Package (WP) lists acronyms and abbreviations that appear in this NMWR.

0001 00-1

NMWR 9-2520-585 0001 00

LIST OF ACRONYMS and ABBREVIATIONS

ABBREVIATION DEFINITION

AEPS Army Electronic Product Support

CAGEC Commercial and Government Entity Code

CPC Corrosion Prevention Control

ECP Engineering Change Proposal

EIR Equipment Improvement Recommendations

FOV Family of Vehicles

HMMWV High Mobility Multipurpose Wheeled Vehicle

NMWR National Maintenance Work Requirement

NSN National Stock Number

OEM Original Equipment Manufacturer

P/N Part Number

QA Quality Assurance

QTY Quantity

RPSTL Repair Parts and Special Tools List

SMR Source, Maintenance, and Recoverability

TACOM Tank-automotive and Armaments Command

TAMMS The Army Maintenance Management System

TAMMS-A The Army Maintenance Management System - Aviation

TM Technical Manual

UOC Usable On Code

WP Work Package

END OF WORK PACKAGE

0001 00-2

NMWR 9-2520-585 0002 00

GENERAL INFORMATION

Scope; Applicable Documents; Definitions; Maintenance Forms, Records, and Reports;

Reporting Equipment Improvement Recommendations (EIRs); Corrosion Prevention and Control (CPC); Quality of Material; Engineering Change Proposals (ECPs); and Differential Rebuild Description.

This NMWR covers the repair of the front and rear differentials, NSN 2520-01-291-2975, P/N 12338415-3; NSN 2520-01-358-3160, P/N 12342615; NSN 2520-01-416-5217, P/N RCSK17305; and NSN 2520-01-498-9104, P/N 12469309. These differentials are used in the High Mobility Multipurpose Wheeled Vehicle (HMMWV). The procedures contained in this NMWR describe disassembly, inspection, component repair, and assembly to ensure a product that is serviceable and issuable to all customers without limitation or restriction, Condition Code A.

APPLICABLE DOCUMENTS

You can receive copies of the applicable documents upon request by contacting:

Department of the Army, United States Army TACOM Life Cycle Management Command, 6501 East 11 Mile Road, Mail Stop 410, ATTN: AMSTA-LCC-CHLD, DAMI_HMMWV@conus.army.mil, Warren, MI 48397-5000.

0002 00-1

APPLICABLE DOCUMENTS (Con’t)

The following documents apply to this NMWR to the extent specified herein.

1. TM 9-2320-280-24P

2. MIL-P-14105C

3. AR 385-10 (Army Safety Program)

4. AR 750-1 (Army Materiel Maintenance Policy)

5. DA PAM 750-8 (The Army Maintenance Management Systems (TAMMS) Users Manual)

6. ISO 9001: 2000 Standards

7. DoD Guide to Uniquely Identifying Items

DEFINITIONS

Rebuild: Consists of those services/actions necessary for the restoration of unserviceable equipment to a like new condition in accordance with OEM standards. Rebuild is the highest degree of material maintenance applied to Army equipment. The rebuild operation includes the action of returning to zero those age measurements (e.g., hours/miles) considered in classifying Army equipment/components.

OEM: The original equipment manufacturer. The company that originally manufactured, fabricated, or supplied an engine component or part. The OEM may include items manufactured by a subcontractor for an OEM provided that the name or trademark of the OEM is shown on the item, label, or container.

After Market Part: Any part or component that has been manufactured or fabricated by a company other than the OEM or their approved subcontractors and sold as a replacement part for an OEM part or component.

Serviceable Part: Any part that is capable of meeting or exceeding the minimum OEM standards for performing the function for which it was originally designed.

Non-serviceable Part: Any part that no longer meets the minimum OEM standards.

Test: To verify serviceability by measuring the mechanical, pneumatic, hydraulic, or electrical characteristics of an item in comparing those characteristics with prescribed standards on a scheduled basis (i.e., load testing of lifting devices and/or hydraulic testing of pressure hoses).

MAINTENANCE FORMS, RECORDS, AND REPORTS

Department of the Army forms and procedures used for equipment will be those prescribed by (as applicable) DA PAM 750-8, The Army Maintenance Management System (TAMMS) Users Manual; DA PAM 738-751, Functional Users Manual for The Army Maintenance Management – Aviation (TAMMS-A); or AR 700-138, Army Logistics Readiness and Sustainability.

0002 00-2

REPORTING EQUIPMENT IMPROVEMENT RECOMMENDATIONS (EIRs)

If your differential assembly (NSNs 2520-01-291-2975, 2520-01-358-3160, 2520-01-416-5217, and 2520-01-498-9104) requires improvements, let us know. Send us an EIR. You, the user, are the only one who can tell us what you don’t like about your equipment. Let us know why you don’t like the design or performance. Put it on a SF 368 (Product Quality Deficiency Report).

Mail it to the address specified in DA PAM 750-8, The Army Maintenance Management System (TAMMS) Users Manual; or as specified by the acquiring activity. We will send you a reply.

CORROSION PREVENTION AND CONTROL (CPC)

1. Corrosion Prevention and Control (CPC) of Army materiel is a continuing concern. It is important that any corrosion problems with this item be reported so that the problem can be corrected and improvements can be made to prevent the problem in future items.

2. While corrosion is typically associated with rusting of metals, it can also include deterioration of other materials such as rubber and plastic. Unusual cracking, softening, swelling, or breaking of these materials may be a corrosion problem.

3. If a corrosion problem is identified, it can be reported using a SF 368. Use of key words such as “corrosion”, “rust”, “deterioration”, or “cracking” will ensure that the information is identified as a CPC problem.

4. The form should be submitted to the address specified in DA PAM 750-8.

QUALITY OF MATERIAL

Parts and material used for replacement, repair, or modification shall meet the requirements of the equipment drawings and specified if standards are not provided in this NMWR.

ENGINEERING CHANGE PROPOSALS (ECPs)

Engineering Change Proposals (ECPs) will be submitted using DD Form 1693 (Engineering Change Proposal [Short form]). (Refer to MIL-STD 973, Configuration Management, for instructions). Completed forms should be mailed directly to Department of the Army, United States Army TACOM Life Cycle Management Command, 6501 East 11 Mile Road, ATTN;

AMSTA-LCC-HLD, DAMI_HMMWV@conus.army.mil , Warren, MI 48397-5000

DIFFERENTIAL REBUILD DESCRIPTION

1. Differential assemblies: NSN 2520-01-291-2975, P/N 12338415-3; NSN 2520-01-358-3160, P/N 12342615; NSN 2520-01-416-5217, P/N RCSK17305; and NSN 2520-01-498-9104, P/N 12469309 will be in various states of disrepair. Determine that component parts conform to established standard(s). Reject all nonconforming parts. All gear teeth, machine surfaces, shims, and bearing caps will be free from embedded metal chips or metal shavings. This standard will provide a serviceable component issuable to all customers without limitation or restriction, Condition Code A.

0002 00-3

DIFFERENTIAL REPAIR DESCRIPTION (Con’t)

2. Some of the old differentials(s) (NSNs 2520-01-293-1626 or 2520-01-188-5115) may be mismarked as NSN 2520-01-291-2975. A description of how to identify each is:

a. OLD STYLE: a 2-piece machined casting with the end cap secured with 3 each ½” X 4-3/4” bolts. The spur gears on the combination spur/worm gear have 9 gear teeth each.

b. NEW STYLE: NSN 2520-01-357-5056 is of a single casting design with only pins to hold the gears in place. The spur gears on the combination spur/worm gear have 18 gear teeth each.

NOTE

The only sure way to determine/identify the correct NSN of the differential is by removing the back cover and visually inspecting the gear unit. All old differential(s) are NSN 2520-01-293-1626 or

NSN 2520-01-188-5115.

3. You can use OEM or equivalent after market repair parts when repairing the differential.

When using other than OEM parts, the parts used must be able to be repaired or replaced using the existing procedures, tools, and repair parts specified in the HMMWV technical manuals.

4. Repaired differential assemblies must maintain the same differential to vehicle interface as the original equipment differential.

5. You may cannibalize serviceable or repairable parts from any unrepairable differential assembly for use when repairing other differential assemblies. For conversion you will replace the differential gear – NSN 2520-01-357-5056 and bearings.

6. During the course of repair, any sub-components/parts of the differential showing obvious signs of imminent failure, excessive wear, or deterioration will be replaced with a fully serviceable replacement.

0002 00-4

CHAPTER 2

MAINTENANCE INSTRUCTIONS

NMWR 9-2520-585 0003 00

DISASSEMBLY

Initial Setup and Disassembly

INITIAL SETUP

Tools General mechanic’s tool kit; automotive WP 0011, Item 1 Dial indicator WP 0011, Item 13

Special Tools Differential housing spreader WP 0011, Item 2 Rear pinion bearing cup remover WP 0011, Item 4 Front pinion bearing cup remover WP 0011, Item 6 Driver handle WP 0011, Item 10 Axle holding fixture adapters WP 0011, Item 12

NOTE

Work area should be clean, well ventilated, and free from blowing dirt and dust.

Refer to axle differential housing identification part number located on housing before ordering any replacement parts.

0003 00-1

DISASSEMBLY

1. Loosen locknut (Figure 1, Item 3) on output shaft assembly (Figure 1, Item 2).

2. Using slide hammer, remove output shaft assembly (Figure 1, Item 2) from differential housing (Figure 1, Item 1).

3. Remove locknut (Figure 2, Item 5), two O-ring seals (Figure 2, Item 4), and output flange (Figure 2, item 3) from output shaft (Figure 2, Item 1).

4. Discard O-ring seals (Figure 2, Item 4), output shaft seal (Figure 2, Item 2), and locknut (Figure 2, Item 5).

5. Repeat steps 1 through 4 for opposite side.

Figure 1. Output Shaft/Differential Assembly

Figure 2. Output Shaft Assembly

0003 00-2

2 4 5

3 2

DISASSEMBLY (Con’t)

6. Install axle holding fixture adapters (Figure 3) on differential housing (Figure 3, Item 3) with four capscrews (Figure 3, Item 4). Place differential housing (Figure 3, Item 3) in holding stand.

7. Position differential housing (Figure 3, Item 3) so differential cover (Figure 3, Item 1) faces up.

Remove twelve capscrews (Figure 3, Item 2) and differential cover (Figure 3, Item 1) from differential housing (Figure 3, Item 3).

Figure 3. Differential Cover

0003 00-3

AXLE HOLDING

FIXTURE ADAPTER

AXLE HOLDING

FIXTURE ADAPTER

CAUTION

Bearing caps must be marked. Failure to comply may result in damage to equipment.

Bearing caps and differential housing are a machine matched set.

Bearing caps must be reinstalled into the original differential housing.

Failure to comply may result in damage to equipment.

Bearing caps might be marked by manufacturer.

Mark each bearing cap left and right, top or bottom. Example:

LT and RT or LB and RB. This is only an example. Use whatever method you wish as long as the bearing caps can be reinstalled properly.

8. Mark bearing caps (Figure 4, Item 1) if not already marked by the OEM in order for bearing caps (Figure 4, Item 1) to be reinstalled in the exact same position as they were removed.

9. Remove four capscrews (Figure 4, Item 2) and two bearing caps (Figure 4, Item 1).

Figure 4. Bearing Caps Marking

0003 00-4

1 1

2 2

10. Install differential housing spreader (Figure 5) into holes in axle holding fixture adapters (Figure 5), and install dial indicator (Figure 5) to read from each end of differential housing (Figure 5, Item 1). Dial indicator (Figure 5) must have preload setting of 0.020 in. (0.5 mm).

Do not over-tighten differential housing spreader.

Failure to comply may result in damage to equipment.

11. Spread differential housing (Figure 5, Item 1) 0.020 in. (0.50 mm) and remove dial indicator (Figure 5).

Figure 5. Differential Housing Spreader

0003 00-5

FIXTURE ADAPTER

DIFFERENTIAL

HOUSING SPREADER

DIAL INDICATOR

AXLE HOLDING

FIXTURE ADAPTER

Tag bearing shims for assembly.

12. Remove differential gear unit (Figure 6, Item 1), two bearing cups (Figure 6, Item 2), and shims (Figure 6, Item 3) from differential housing (Figure 6, Item 4). Discard bearing cups (Figure 6, Item 2).

13. Relieve pressure on differential housing spreader (Figure 6) and remove from differential housing (Figure 6, Item 4).

Figure 6. Differential Case

0003 00-6

DIFFERENTIAL

HOUSING SPREADER

14. Rotate differential housing (Figure 7, Item 1) 90°.

15. Remove pinion locknut (Figure 7, Item 6) securing pinion yoke (Figure 7, Item 5) to pinion gear (Figure 7, Item 7).

16. Remove pinion yoke (Figure 7, Item 5) from pinion gear (Figure 7, Item 7).

17. Re-install pinion locknut (Figure 7, Item 6) hand tight.

18. Drive pinion gear (Figure 7, Item 7) out of front pinion bearing (Figure 7, Item 2).

19. Remove pinion locknut (Figure 7, Item 6) and discard pinion locknut (Figure 7, Item 6).

20. Remove pinion gear (Figure 7, Item 7) and collapsible spacer (Figure 7, Item 8) from differential housing (Figure 7, Item 1). Discard collapsible spacer (Figure 7, Item 8).

21. Remove pinion seal (Figure 7, Item 3) and front pinion bearing (Figure 7, Item 2) and dirt deflector (Figure 7, Item 4) from differential housing (Figure 7, Item 1). Discard pinion seal (Figure 7, Item 3) and front pinion bearing (Figure 7, Item 2).

Figure 7. Pinion Assembly

0003 00-7

22. Using driver handle (Figure 8) and rear pinion bearing cup remover (Figure 8), remove rear pinion bearing cup (Figure 8, Item 3) and pinion depth shim (Figure 8, Item 4) from differential housing (Figure 8, Item 1). Discard rear pinion bearing cup (Figure 8, Item 3).

23. Rotate differential housing (Figure 8, Item 1) 180°. Using driver handle (Figure 8) and front pinion bearing cup remover (Figure 8), remove front pinion bearing cup (Figure 8, Item 2) from differential housing (Figure 8, Item 1). Discard front pinion bearing cup (Figure 8, Item 2).

Figure 8. Bearing Cup Installation

0003 00-8

DRIVER HANDLE

DRIVER HANDLE

REAR PINION

BEARING CUP

REMOVER FRONT PINION

BEARING CUP

REMOVER

Do not chisel or wedge ring gear from differential case. Failure to comply may result in damage to equipment.

24. Remove eight capscrews (Figure 9, Item 2) and ring gear (Figure 9, Item 3) from differential case (Figure 9, Item 1).

Figure 9. Ring Gear

25. Use press to remove two differential side bearings (Figure 10, Item 2) from differential gear unit (Figure 10, Item 1). Discard differential side bearings (Figure 10, Item 2).

Figure 10. Differential Side Bearings

0003 00-9

2 2

26. Remove rear pinion bearing (Figure 11, Item 1) from pinion gear (Figure 11, Item 2).

Discard rear pinion bearing (Figure 11, Item 1).

27. Remove bearing (Figure 11, Item 4) from output shaft (Figure 11, Item 3). Discard bearing (Figure 11, Item 4).

28. Repeat step 27 for opposite side.

Figure 11. Rear Pinion Bearing

END OF TASK

0003 00-10

NMWR 9-2520-585 0004 00

CLEANING AND INSPECTION

Cleaning; General Inspection; and General Repair

CLEANING:

1. General Instructions. Cleaning procedures will be the same for the majority of parts and components which make up the vehicle subassemblies. Procedures for cleaning will be done in accordance with best commercial and/or local practices. Parts and/or components that require special or specific cleaning procedures will be addressed within this WP. General cleaning procedures are detailed in Steps “2” through “7” .

2. The Importance of Cleaning. Great care and effort are required in all cleaning operations. The presence of dirt and foreign material is a constant threat to satisfactory vehicle operation and maintenance. The following will apply to all cleaning operations:

a. Hands must be kept free of any accumulation of grease, which can collect dust and grit.

b. Clean all parts before inspection, after repair, and before assembly.

c. After cleaning, all parts must be covered or wrapped in plastic or paper to protect them from dust and/or dirt.

3. Disassembled Parts Cleaning. Place all disassembled parts in wire baskets for cleaning.

a. Dry and cover all cleaned parts.

b. Place on or in “racks” and hold for inspection or repair.

c. All parts subject to rusting must be lightly coated with oil and wrapped.

d. Keep all related parts and components together. Do not mix parts.

0004 00-1

CLEANING (Con’t)

WARNING

Improper cleaning methods and use of unauthorized cleaning solutions may injure personnel and damage equipment.

4. Castings.

a. Clean inner and outer surfaces of castings and all areas subject to grease and oil with degreasing solvents.

b. Use a stiff brush to remove sludge and gum deposits.

Compressed air used for cleaning purposes must not exceed 30 psi (207 kPa). Use only with effective chip guarding and personal protective equipment (goggles/shields, gloves, etc.). Failure to comply may result in injury to personnel and/or damage to equipment.

c. Use compressed air to blow out all tapped capscrew holes and dry castings after cleaning.

5. Oil Passages. Particular attention must be given to all oil passages in castings and machines parts. Oil passages must be clean and free of any obstructions.

a. Clean passages with wire probes to break up any sludge or gum deposits.

b. Wash passages by flushing with degreasing solvents.

c. Dry passages with compressed air.

CAUTION

Do not allow degreasing solvents to come in contact with seals, cables, or flexible hoses. These cleaners cause leather, rubber, and synthetic materials to dry out, rot, and lose pliability making them unserviceable.

6. Nonmetallic parts. Clean hoses and other nonmetallic parts with soap and water.

0004 00-2

CLEANING (Con’t)

7. Electrical Components.

a. Clean electrical components with clean cloth dampened with degreasing solvent. Care must be taken not to damage protective insulation.

Compressed air used for cleaning purposes must not exceed 30 psi (207 kPa). Use only with effective chip guarding and personal protective equipment (goggles/shields, gloves, etc.). Failure to comply may result in injury to personnel and/or damage to equipment.

b. Use compressed air to dry electrical components.

END OF TASK

GENERAL INSPECTION

1. General Instructions. Procedures for inspections will be the same for many parts and components which make up the vehicle subassemblies. General procedures are detailed in Steps “2” through “11”. Dimensional standards for parts have been fixed at extremely close tolerances, so use specification tables. Use specified inspection equipment for inspection where cracks and other damage cannot be spotted visually. Exercise extreme care in all phases of inspection. Repair or replace all unserviceable components.

2. Castings.

a. Inspect all ferrous and nonferrous castings for cracks. See ASTM E-1444-05 (Inspection, Penetrant Methods). Particularly check areas around studs, pipe plugs, threaded inserts, and sharp corners. Replace cracked castings.

b. Inspect machined surfaces for nicks, burrs, and raised metal. Mark damaged areas for repair or replacement.

c. Inspect all pipe plug openings and capscrew openings for damage and stripped threads.

Replace if damaged. If stripped threads cannot be repaired, replace components.

d. Check all gasket mating surfaces, flanges on housings, and supports for warpage with a straightedge or surface place. Inspect mating flanges for discolorations which may indicate leakage. Replace if warped.

e. Check all castings for conformance to applicable repair standards.

0004 00-3

GENERAL INSPECTION (Con’t)

3. Machined Parts.

a. Check machined parts for cracks, distortion, and damage.

b. Check all surfaces for nicks, burrs, and raised metal.

4. Studs, Bolts, Capscrews, and Nuts. Replace if bent, loose, stretched, or threads are damaged.

5. Gears.

NOTE

When gear teeth wear limits are not established, good judgment is required to determine if gear replacement is necessary

a. Inspect all gears for cracks and missing teeth. Replace if cracked or teeth are missing.

b. Inspect gear teeth for wear, sharp fins, burrs, and galled or pitted surfaces.

c. Inspect splines for wear, burrs, and galled or pitted surfaces.

d. Check keyway slots for wear and/or damage.

6. Geared Units.

NOTE

Inspection procedure for differentials is already converted to the new Differential Gear Unit, NSN 2520-01-357-5056.

a. Remove differential gear unit from the differential housing.

b. Clean gear unit.

c. Insert axle shafts into gear unit and manually turn axle shafts both clockwise and counterclockwise to get a full 360° turn on the gears while visually inspecting the center gear and all three sets of worm/spur gears for chipped/broken gear teeth, scarring, discoloration, and sharp/knifed edges on the worm gears. Minor scarring and discoloration of gears is allowable. Replace gear unit if gears are broken or knifed edged. A single chipped spur gear per set is allowable. Replace differential gear unit if more than a single chipped spur gear per set is found.

d. While turning the shafts, gears must turn freely and smoothly. Evidence of binding is not allowed.

0004 00-4

e. Measure the end play (thrust) of the center gear with feeler gauges between the thrust washer and center gear. Measurement is taken at the end opposite side of the ring gear mounting. Turn the axle shafts to ensure that the center gear is tight against the thrust washers at the ring gear end before taking reading. If the measurement is 0.074 (+ 0.000”, -0.003”), the differential gear unit must be replaced.

f. Scoring around the outside of the gear unit housing from the pinion gear is evidence of pinion gear bearing failure or loss of the pre-load on the pinion shaft. If gouging is deeper than 0.0625” (1/16”), the gear unit must be replaced. Slight “metal peen over” can be dressed up with a file ensuring that the filings do not get into the gear unit. Any “metal peen over” in the area of the spur/worm gears must not interfere with the rotation of the gears. (The 1/16” is an approximate measurement that the mechanic’s judgment and expertise is taken into account how wide the scoring is and if it goes all the way around the gear housing.)

7. Oil Seals. Oil seals are mandatory replacement items.

8. Casting Plugs. Inspect for leakage. Replace plugs when leakage is present.

9. Springs. Inspect for damaged, distorted, and collapsed coils.

10. Snap Rings, Retaining Rings, and Washers. Many of these parts are mandatory replacement items. Inspect all others for obvious damage.

11. Differential Housing: Inspect differential housing (Figure 1, Item 1) and all threaded holes for damage. Repair any damaged threads with thread repair inserts. Replace differential if differential housing (Figure 1, Item 1) is damaged.

Figure 1. Differential Housing

0004 00-5

Ring and pinion gears must be replaced as matched set.

12. Splines and Gear Teeth. Inspect splines and gear teeth on pinion gear (Figure 2, Item 1) and ring gear (Figure 2, Item 2) for damaged or broken teeth and wear. Replace both pinion gear (Figure 2, Item 1) and ring gear (Figure 2, Item 2) if either are damaged or worn out.

Figure 2. Gears

0004 00-6

13. Splines and Sealing Surfaces. Inspect splines and sealing surfaces on output flanges (Figure 3, Item 1), pinion yoke (Figure 3, Item 2), axle slinger (Figure 3, Item 3), and output shafts (Figure 3, Item 5) for damage. Replace if damaged.

NOTE

If rear pinion yoke is being replaced, a new slinger must be installed on new pinion yoke.

Push rear pinion yoke into slinger until slinger is seated against rear shoulder of yoke.

14. Differential Gear Unit. Inspect differential gear unit (Figure 3, Item 4) for damage.

Replace if damaged.

Figure 3. Differential Components

0004 00-7

4 5

CLEANING AND INSPECTION (Con’t)

GENERAL REPAIR

1. General Instructions. Repair of most parts and components is limited to general procedures outlined in applicable maintenance instructions and the following detailed procedures “2” through “8” .

CAUTION

Repaired items must be thoroughly cleaned to remove metal chips and abrasives to prevent them from entering working parts of vehicle components.

2. Castings.

a. All cracked castings will be replaced.

b. Only minor repairs to machined surfaces, flanges, and gasket mating surfaces are permitted. Remove minor nicks, burrs, and/or scratches by:

(1) Using fine mill file.

(2) Using abrasive cloth dipped in cleaning solvent.

(3) Lapping across a surface plate.

(4) Re-machining of machined surface to repair damage, warpage, or uneven surfaces is not permitted.

c. Repair damaged threaded pipe plugs and/or capscrew holes with a thread tap or repair oversize holes with threaded inserts.

3. Bearings. Bearings are mandatory replacement items.

4. Stud(s). Replace all bent and stretched stud(s). Repair minor thread damage with a thread restorer file. Replace stud(s) having stripped or damaged threads as outlined below:

a. Remove using a stud remover. Back stud(s) out slowly to avoid heat buildup and seizure, which can cause stud(s)to break off.

b. If stud(s) are broken off too short to use a stud remover, use extractor to remove stud(s).

c. Replacement studs have a special coating and must have a small amount of anti-seize compound (NSN 8030-00-059-2761) applied on threads before stud(s) is installed. Install replacement stud(s) slowly to prevent heat buildup, damage to threads, or breaking of studs.

0004 00-8

GENERAL REPAIR (Con’t)

5. Gears.

a. Remove gears using pullers, as required.

b. Use the same methods described in paragraph 2.b. (WP 0004) for castings to remove minor nicks, burrs, or scratches on gear teeth.

c. If keyways are worn or enlarged, replace gear.

6. Bushings and Bushing Type Bearings. When bushings and bushing type bearings seize to a shaft and spin in the bore, the associated part must also be inspected and replaced, as required.

7. Oil Seals.

a. Remove oil seals, being careful not to damage casting or adapter bore.

b. Always install new seal in bore using proper seal replacing tool.

8. Locking Threads. When using thread sealing compound:

a. Apply a liberal amount to both male and female threads on through-hold assemblies.

b. Apply a liberal amount into the bottom of a blind hole (non-through hole assemblies).

Installing the fastener pneumatically forces the adhesive onto the threads.

c. Assemble parts shortly after applying thread sealing compound to allow adequate coating of threads.

0004 00-9/10 blank

NMWR 9-2520-585 0005 00

ASSEMBLY

Initial Setup and Assembly

INITIAL SETUP

Tools

General mechanic’s tool kit; automotive WP 0011, Item 1

Special Tools Differential housing spreader WP 0011, Item 2 Pinion setting gauge set WP 0011, Item 3 Rear pinion bearing cup remover WP 0011, Item 4 Rear pinion bearing cup installer WP 0011, Item 7 Front pinion bearing cup installer WP 0011, Item 8 Yoke seal installer WP 0011, Item 9 Driver handle WP 0011, Item 10 Output shaft installer WP 0011, Item 11 Axle holding fixture adapters WP 0011, Item 12 Dial Indicator WP 0011, Item 13 Torque wrench lb in 3/8 dr WP 0014, Item 14

Material/Parts O-ring packing WP 0012, Item 2 Nut, self-locking WP 0012, Item 1 Spacer, sleeve WP 0012, Item 5 Pinion seal WP 0012, Item 3 Two output shaft seals WP 0012, Item 4 Side bearing WP 0012, Item 6 Output bearing WP 0012, Item 7 Front rear bearing WP 0012, Item 8 Rear pinion bearing WP 0012, Item 9 Silicone sealant WP 0013, Item 9 Lubricating oil WP 0013, Item 8 Sealing compound WP 0013, Item 5

0005 00-1

ASSEMBLY

Pinion gear depth is the distance from the end face of the pinion to the center line of the output shafts. The dimension is controlled by shims between pinion gear rear bearing cup and differential housing. The pinion gear is etched with two identifying numbers. The first number identifies ring gear and pinion gear as a matched set; the second number represents “pinion depth variance” and is preceded by a plus (+) or minus (-). This number represents the amount in thousandths the gear set varied from the “standard setting”

2.547 in. (6.46 cm).

1. Install fixture holding fixture adapter (Figure 1) on differential housing (Figure 1, Item 1) with four capscrews (Figure 1, Item 2). Place differential housing (Figure 1, Item 1) in holding stand.

Figure 1. Differential Cover Installation

0005 00-2

FIXTURE HOLDING

FIXTURE ADAPTER

ASSEMBLY (Con’t)

2. Rotate differential housing (Figure 2, Item 2) so front pinion bearing cup (Figure 2, Item 1) bore faces up.

3. Lubricate outside diameter of front pinion bearing cup (Figure 2, Item 1) with lubricating oil.

Using driver handle (Figure 2) and front pinion bearing cup installer (Figure 2), install front pinion bearing cup (Figure 2, Item 1) in differential housing (Figure 2, Item 2).

4. Rotate differential housing (Figure 2, Item 2) 90°.

Figure 2. Bearing Cup Installation

0005 00-3

DRIVER HANDLE

FRONT PISTON

BEARING CUP INSTALLER

5. Using pinion setting gauge set, install blocks (Figure 3), rear pinion bearing cup (Figure 3, Item 3), rear pinion bearing (Figure 3, Item 4), and pilot washers (Figure 3) on stud (Figure 3) and secure with blocks (Figure 3).

6. Position stud (Figure 3) assembly in differential housing (Figure 3, Item 1), and install with front pinion bearing (Figure 3, Item 2), pilot washers (Figure 3), and nut (Figure 3). Tighten nuts (Figure 3) to 10 lb-in. (1.13 N•m). Rotate the stud (Figure 3) assembly several revolutions to seat the bearings and recheck the torque.

Figure 3. Pinion Bearing Cup Installation

7. Rotate front of differential housing (Figure 4, Item 2) downward 90°. Assemble arbor (Figure 4) and two discs (Figure 4) and install in differential housing (Figure 4, Item 2).

8. Install two bearing caps (Figure 4, Item 3) and four capscrews (Figure 4, Item 1) in differential housing (Figure 4, Item 2) and finger tighten capscrews (Figure 4, Item 1).

Figure 4. Arbor Installation

0005 00-4

ARBOR

DISCs

9. Position arbor (Figure 5) on block (Figure 5), and install dial indicator (Figure 5) to arbor post (Figure 5). Preload the dial indicator (Figure 5) until the needle rotates approximately one full turn clockwise. Tighten the dial indicator (Figure 5) in this position and recheck dial indicator (Figure 5) to ensure it is at zero reading.

10. Rotate gauge shaft (Figure 5) slowly back and forth until the dial indicator (Figure 5) reads the greatest deflection. At the point of greatest deflection, set the dial indicator (Figure 5) to zero. Repeat the rocking action of the gauge shaft (Figure 5) to verify the gauge setting.

11. After the zero setting is obtained, rotate gauge shaft (Figure 5) until the dial indicator (Figure 5) plunger does not touch the block (Figure 5).

Figure 5. Pinion Shim Measurement

12. Record the number of the dial indicator reading (Figure 6). Example: If the pointer moved clockwise and stops between 0 and 11, add .100" to measurement for shim thickness. If the pointer moves counterclockwise and stops between 84 and 99, correct shim thickness is indicated.

Figure 6. Dial Indicator Reading

0005 00-5

DIAL INDICATOR

ARBOR POST

ARBOR

BLOCK

GAUGE SHAFT

This reading indicates the shim thickness that is required of a pinion that is etched with a zero (0) on the pinion head. If the pinion being installed has a plus (+) or minus (-) etching, then an adjustment of the shim thickness is required. Example: If a pinion is etched “+3", then .003" less shim thickness is required. Subtract .003" from the dial indicator reading. If a pinion is etched "-3", then .003" more shim thickness is required. Add .003" to the dial indicator reading.

13. Remove dial indicator (Figure 7) from arbor (Figure 7).

14. Remove four capscrews (Figure 7, Item 1), two bearing caps (Figure 7, Item 3), two discs (Figure 7), and arbor (Figure 7) from differential housing (Figure 7, Item 2).

Figure 7. Arbor Installation

0005 00-6

ARBOR

DISCs

DIAL INDICATOR

15. Remove nut (Figure 8), pilot washers (Figure 8), front pinion bearing (Figure 8, Item 2), and stud (Figure 8) assembly from differential housing (Figure 8, Item 1).

16. Remove blocks (Figure 8), pilot washers (Figure 8), rear pinion bearing (Figure 8, Item 4), rear pinion bearing cup (Figure 8, Item 3), and blocks (Figure 8) from stud (Figure 8).

Figure 8. Pinion Bearing Cup Installation

0005 00-7

17. Lubricate outside diameter of rear pinion bearing cup (Figure 9, Item 1) with lubricating oil.

If pinion shim is beveled, be sure beveled side faces bottom of bearing cup bore.

18. Using driver handle (Figure 9) and rear pinion bearing cup installer (Figure 9), install correct thickness pinion shim (Figure 9, Item 2) and rear pinion bearing cup (Figure 9, Item 1) in differential housing (Figure 9, Item 3).

Figure 9. Pinion Shim and Bearing Cup Installation

0005 00-8

DRIVER

HANDLE

REAR PINION

BEARING CUP

INSTALLER

19. Use press and install rear pinion bearing (Figure 10, Item 1) on pinion gear (Figure 10, Item 2).

Figure 10. Pinion Gear

20. Rotate differential housing (Figure 11, Item 1) 90°. Lubricate rear pinion bearing (Figure 11, Item 2) with lubricating oil.

CAUTION

Collapsible spacer controls pinion bearing preload. Do not reuse old spacer. Failure to comply may result in damage to pinion bearing.

21. Install collapsible spacer (Figure 11, Item 4) on pinion gear (Figure 11, Item 3), and install pinion gear (Figure 11, Item 3) in differential housing (Figure 11, Item 1).

Figure 11. Pinion and Yoke Installation

0005 00-9

2 3

22. Lubricate front pinion bearing (Figure 12, Item 2) and pinion seal (Figure 12, Item 4) with lubricating oil. Using yoke seal installer (Figure 12, Item 1), install front pinion bearing (Figure 12, Item 2) and pinion seal (Figure 12, Item 4) in differential housing (Figure 12, Item 3).

Figure 12. Differential Bearing and Seal Installation

23. Install pinion yoke (Figure 13, Item 2), slinger (Figure 13, Item 1), and locknut (Figure 13, Item 3) on pinion gear (Figure 13, Item 4).

Figure 13. Pinion and Yoke Installation

0005 00-10

Do not exceed specified preload torque on pinion bearings.

Failure to comply may result in premature failure of bearings.

Do not loosen locknut to replace preload torque. Failure to comply may result in damage to pinion bearing.

If specified torque is exceeded, remove pinion gear and replace collapsible spacer and locknut and adjust preload again. Failure to comply may result in premature failure of bearings.

24. Tighten locknut (Figure 14, Item 3) only enough to remove end play and seat pinion bearings in differential housing (Figure 14, Item 1). Rotate pinion yoke (Figure 14, Item 2) while tightening to seat bearings evenly.

25. Measure torque required to rotate pinion gear (Figure 14, Item 4). Correct pinion bearing preload torque is 17-25 lb-in. (2-3 N•m) with new bearings.

26. Continue to tighten locknut (Figure 14, Item 3) in small increments until pinion bearing preload torque meets specifications.

27. Rotate differential housing (Figure 14, Item 1) 90°.

Figure 14. Pinion and Yoke Installation

0005 00-11

28. Use press and install two side bearings (Figure 15, Item 1) on differential gear unit (Figure 15, Item 2).

Figure 15. Differential Gear Unit

Side bearing shims are available in thickness from 0.077 - 0.117 in (1.95-2.97 mm) in increments of 0.001 in. (.025 mm).

29. Rotate differential housing (Figure 16, Item 4) downward 90°. Install two side bearing cups (Figure 16, Item 2) and side bearings shims (Figure 16, Item 3) on side bearings (Figure 16, Item 1). Use 0.080 in. (2 mm) side bearing shims (Figure 16, Item 3) as a starting point.

Figure 16. Gear Unit Installation

0005 00-12

1 3

1 1 2

30. Install differential gear unit (Figure 17, Item 2), two side bearing cups (Figure 17, Item 4), and two side bearing shims (Figure 17, Item 5) in differential housing (Figure 17, Item 6).

31. Install two bearing caps (Figure 17, Item 3) and four capscrews (Figure 17, Item 1) in differential housing (Figure 17, Item 6). Snug four capscrews (Figure 17, Item 1).

Figure 17. Gear Unit Installation

32. Mount dial indicator (Figure 18) on differential housing (Figure 18, Item 3) and index dial indicator (Figure 18, Item 1) to read off ring gear mounting surface of differential gear unit (Figure 18, Item 2).

33. Pry between differential gear unit (Figure 18, Item 2) and bearing cap (Figure 18, Item 1) on one side and zero dial indicator (Figure 18, Item 1). Pry on opposite side to read end play.

Figure 18. Side Bearing Shim Measurement

0005 00-13

3 3

1 1

1 2

34. Amount read on dial indicator (Figure 19) is shim thickness that should be added to side bearing shims (Figure 19, Item 3) to arrive at zero end play. Add necessary side bearing shims (Figure 19, Item 3) and repeat procedure to ensure accuracy.

35. Tighten four capscrews (Figure 19, Item 2) to 55–70 lb-ft (75–95 N•m).

36. Rotate differential gear unit (Figure 19, Item 1) and check runout. Runout should not exceed 0.002 in. (0.05 mm).

37. Remove dial indicator (Figure 19) from differential housing (Figure 19, Item 4).

Figure 19. Gear Unit Installation/Bearing Shim Measurement

0005 00-14

Tag shims and bearing cups for assembly.

38. Remove four capscrews (Figure 20, Item 3), two bearing caps (Figure 20, Item 2), differential gear unit (Figure 20, Item 1), two side bearing cups (Figure 20, Item 4), and side bearing shim(s) (Figure 20, Item 5) from differential housing (Figure 20, Item 6).

Figure 20. Gear Unit Installation

0005 00-15

If ring gear was removed perform steps 39 – 43.

If not, proceed to step 44.

39. Install four guide pins (Figure 21) in ring gear (Figure 21, Item 2).

40. Support ring gear (Figure 21, Item 2) with wood blocks in press.

41. Press differential gear unit (Figure 21, Item 3) on ring gear (Figure 21, Item 2).

42. Remove four guide pins (Figure 21) from ring gear (Figure 21, Item 2).

43. Apply sealing compound and install eight capscrews (Figure 21, Item 1). Tighten eight capscrews (Figure 21, Item 1) to 95-115 lb-ft (129-156 N•m).

Figure 21. Ring Gear Installation

0005 00-16

PINS

Do not over-tighten differential housing spreader.

Failure to comply may result in damage to equipment.

44. Install differential housing spreader (Figure 22) into holes in axle holding fixture adapters (Figure 22) and install dial indicator (Figure 22) to read from each end of differential housing (Figure 22, Item 1). Dial indicator (Figure 22) must have preload setting of 0.020 in.

(0.50 mm).

45. Spread differential housing (Figure 22, Item 1) 0.020 in. (0.50 mm) and remove dial indicator (Figure 22).

Figure 22. Differential Spreader

0005 00-17

AXLE HOUSING

FIXTURE ADAPTER

DIFFERENTIAL

HOUSING SPREADER

DIAL INDICATOR

AXLE HOLDING

46. Install two side bearing shims (Figure 23, Item 3), two side bearing cups (Figure 23, Item 2), and differential gear unit (Figure 23, Item 1) in differential housing (Figure 23, Item 4).

Figure 23. Differential Gear Unit Installation

47. Remove differential housing spreader (Figure 24).

Figure 24. Differential Spreader

0005 00-18

HOUSING SPREADER

Install bearing caps exactly the same way they were removed.

Failure to comply may result in damage to differentials.

48. Install two bearing caps (Figure 25, Item 1) with four capscrews (Figure 25, Item 2) in differential housing (Figure 25, Item 3). Tighten four capscrews (Figure 25, Item 2) to 55-70 lb-ft (75-95 N•m).

Figure 25. Differential Gear Unit Installation

0005 00-19

49. Attach dial indicator (Figure 26) to differential housing (Figure 26, Item 3) and index dial indicator (Figure 26) to read…