GENERAL MAINTENANCE INSTRUCTIONS

TM 9-2815-225-34&P · Work Package 0051 00

THIS WORK PACKAGE (WP) COVERS:

Scope; Precautions; Special Processes; Tools and Equipment; Disassembly; Cleaning; Inspection—Acceptance and Rejection Criteria; Repair or Replacement; and Assembly.

SCOPE

This WP contains general maintenance instructions pertaining to disassembly, cleaning, inspection, repair, and assembly of the Cummins NTC-400 diesel engine. Detailed information will be found in specific WPs. The repair procedures in this manual are for use at direct support and general support maintenance levels. All information contained in this manual applies to both Big Cam I and Big Cam III engines except where differences are specifically noted.

PRECAUTIONS

All material-handling equipment shall be adequate to ensure safe working conditions for personnel and efficient processing of items.

The component shall be properly mounted on a fixture for disassembly and assembly to ensure safe working conditions.

Follow all WARNINGS, CAUTIONS, and NOTES included in specific WPs to ensure personnel safety and prevent damage to equipment.

SPECIAL PROCESSES

Special processes and equipment required for maintenance operations, as specified in this manual, are defined or referenced at the point of their application. When a special process is required, the maintenance activity (when requested) shall provide evidence of compliance with controlling specifications. Following is a summary of some of the special processes that may be required for this manual. Table 1. Special Processes.

SPECIAL PROCESS                                          DESCRIPTION

E 1417, Standard Practice for Liquid Penetrant Examination, is followed when using fluorescent or Liquid Penetrant Inspection visible dye to detect cracks, flaws, etc., open to the surface of any nonporous metal.

E 1444, Standard Practice for Magnetic Particle Magnetic Particle Inspection Examination, is used to detect cracks, etc., at or below surface of ferrous (ferromagnetic) metals.

TOOLS AND EQUIPMENT

Tools and equipment required to overhaul this component can be found in Tools and Special Tools, WP 0061 00. Torque wrench specifications are given in text, as applicable. Metric equivalents are in parentheses following the U.S. standard measurement. (Example: Tighten oil pump mounting bolts 33–40 lb-ft (45–54 N•m).) Standard capscrew markings and torque specifications are found in Torque Limits, WP 0053 00. Tolerances, torque values, and adjustments are provided in each WP as necessary.

DISASSEMBLY

Each appropriate WP will contain specific instructions for disassembly of the components. Take care in handling parts during disassembly. Nicks, scratches, or other damage caused by careless handling may cause premature failure of equipment. Matched, married, or mated items (examples: bearings and races, covers and housings, and some gear sets) should be fastened together or otherwise identified as parts being processed together. If one part fails inspection, both parts must be replaced as a set.

CLEANING

For authorized cleaning materials, refer to TM 9-247, Materials Used for Cleaning, Preserving, Abrading, and Cementing. Remove all rust and surface scale using a wire brush, sand blast, grit blast, or other effective methods in accordance with standard procedures.

INSPECTION—ACCEPTANCE AND REJECTION CRITERIA

Throughout this manual, measurements are used to confirm serviceability of items after a visual inspection. Measurements will be performed as required by quality assurance, in-process inspection, maintenance procedures, engine test report, and Final Inspection Report (FIR). Used components and refinished parts, recovered as products of disassembly, will be examined 100 percent to determine serviceability by contractor. Refer to the maintenance WPs, work directive, or contract for more detail. Parts showing evidence of overheating are unrepairable by any process. Discard these parts.

Table 2. General Inspection Guidelines.

INSPECT                                                ACTION

Remove all obstructions with compressed air or by Oil passages working a soft wire back and forth through oil passage.

Inspect threads for minor irregularities. For Threads (internal and external) damaged thread repair, refer to table 3, Repairable Defects.

Check for damage that could cause oil leakage or Machined surfaces malfunction of the part. Refer to table 3, Repairable Defects.

Check for nicks, burrs, or scoring. If any such Gear conditions are found, refer to table 3, Repairable Defects.

REPAIR OR REPLACEMENT

Parts that are beyond wear limit tolerances, broken, cracked, or otherwise damaged may be considered for repair by special processes listed below by requesting approval from TACOM. In requesting approval, the maintenance activity will furnish:

1. Written repair procedure

2. Specifications covering the procedure

3. Reference drawing

Unrepairable Defects Do not repair any of the following:

1. Casting cracks at through-bores, threaded holes, or high-stress areas

2. Cracked, chipped, ridged, or pitted gear teeth

3. Cracked or split keyways

4. Scored or scratched bores

5. Cracked or chipped snapring grooves

6. Oil channels with cracked walls or chipped edges

7. Pitted or grooved gear teeth, unless otherwise indicated in this manual

8. Parts showing evidence of overheating

9. Chipped edges, burred sealing ridges, and longitudinal scratches on sealing surfaces

Repairable Defects

Table 3. Repairable Defects.

REPAIRABLE PART/AREA                                     REPAIR PROCESS

Machined surfaces Small burrs and scratches may be removed with a fine mill file or fine grit emery cloth. Discard components that have burrs or scratches too large to repair. Cylinder block and cylinder head can be resurfaced to correct surface defects and warpage.

Damaged external threads Repair threads having slight irregularities. Remove burrs with a soft stone, fine mill file, or emery cloth. Clean up slight irregularities by running thread die of correct size over thread. Discard components not repairable. Damaged internal threads Repair threads in tapped holes having minor irregularities by retapping with correct size previously used hole tap. Drill-out tapped holes having badly damaged threads and install a threaded insert. Follow kit manufacturer's and NASM33537 instructions. When drilling, the land width (space between holes, or between edge of hole and edge of material) must measure no less than three-fourths of the hole diameter. Discard components not repairable.

Housing; castings; and Unless otherwise indicated, use fine emery cloth, crocus cloth, or soft stone shaped, machined surfaces to repair minor nicks, burrs, and scoring. Minor surface irregularities on noncontact surfaces do not need repair. Discard components not repairable.

Gears, splines, and shafts Use crocus cloth, fine mill file, or soft stone to remove minor nicks, burrs, and scoring. Welding, grinding, machining, plating, etc. of gears to correct defects is not authorized. Discard components not repairable.

Surface rust and corrosion Remove surface rust and corrosion from all internal parts and surfaces. Mechanical and/or chemical methods may be used. Use fine emery cloth, crocus cloth, or soft stone to remove minor surface rust and corrosion. Do not assemble components having rusted or corroded parts. Corrosion or rust may flake off and cause damage to component while circulating in oil during operation. Discard components not repairable.

ASSEMBLY

Cleanliness is essential in all component assembly operations. Dust and dirt, even in minute quantities, are abrasive. Parts must be kept clean. See individual WPs for specific assembly instructions. Replace any part that does not pass visual inspection or that is outside specified wear limits listed in the maintenance WPs. Follow WP instructions for coating bearings, bushings, gears, shafts, seals, friction parts, and other contact surfaces with operating oil (engine oil for engine parts, etc.) to ensure lubrication of parts during initial operation after repair. Seal handling:

1. Do not open seal packets until ready to install seal. Seals may become contaminated with dust or dirt. Some types of seals can absorb moisture, which may cause damage during installation and/or shorten the lifespan of the seals.

2. Ensure lip-type seals are installed so spring-loaded lip faces toward lubricant. Tighten all capscrews, screws, bolts, nuts, and fittings to torque values specified in maintenance WPs and in WP 0053 00. For parts identification, refer to WP 0058 00.

END OF WORK PACKAGE