M939 M939A1 M939A2 5-Ton 6×6 Truck Maintenance Manual Volume 1 – TM 9-2320-272-24-1

Description

M939 M939A1 M939A2 5-Ton 6×6 Truck Maintenance Manual Volume 1 – TM 9-2320-272-24-1

This June 1998 technical manual covers unit, direct support, and general support maintenance information for the diesel 5-ton, 6×6 M939, M939A1, and M939A2 series trucks. Volume 1 brings together vehicle identification and system operation, preventive maintenance, detailed unit troubleshooting, and the first nine sections of unit maintenance. The procedures are written for maintenance personnel and are supported by locator illustrations, exploded views, cut-away diagrams, system schematics, test steps, adjustment data, safety notes, and task-specific setup information.

Volume 1 Scope

The M939 M939A1 M939A2 5-Ton 6×6 Truck Maintenance Manual Volume 1 – TM 9-2320-272-24-1 is Volume 1 of a four-volume publication. This volume contains Chapters 1 and 2 and Chapter 3 through Section IX. It also includes the table of contents for the complete four-volume publication and an alphabetical index for tasks contained in this volume. Buyers looking specifically for the later Unit Maintenance sections, Direct Support maintenance, General Support maintenance, shipment/storage material, or appendices should note that those portions are assigned to other volumes of the publication.

Vehicles and Configurations Covered

The manual covers the M939, M939A1, and M939A2 5-ton 6×6 diesel truck families across cargo, dump, tractor, expansible-van, and medium-wrecker configurations. Model-specific procedures and notes are used where equipment or systems differ.

• M923, M923A1, M923A2 – cargo, dropside models
• M925, M925A1, M925A2 – cargo, dropside models with winch
• M927, M927A1, M927A2 – extra-long-wheelbase cargo models
• M928, M928A1, M928A2 – extra-long-wheelbase cargo models with winch
• M929, M929A1, M929A2 – dump trucks
• M930, M930A1, M930A2 – dump trucks with winch
• M931, M931A1, M931A2 – tractor trucks
• M932, M932A1, M932A2 – tractor trucks with winch
• M934, M934A1, M934A2 – expansible vans
• M936, M936A1, M936A2 – medium wreckers

The equipment description section identifies important series differences. M939/A1 series vehicles use the Cummins NHC 250 engine, while M939A2 series vehicles use the Cummins 6CTA8.3 diesel. The M939A2 series also incorporates the Central Tire Inflation System (CTIS). The manual explains model differences in body type, fuel-tank arrangements, tire sizes, wheelbases, winch applications, and special-purpose equipment before moving into maintenance and troubleshooting.

Diagnosis, PMCS, and Task Procedures

This volume is much more than a component-removal guide. The preventive maintenance section provides systematic inspection, servicing, adjustment, and correction procedures intended to identify faults before they become larger failures. The schedule includes semiannual, annual, and biennial checks, with semiannual service identified as every 6 months or 6,000 miles, annual service as every 12 months or 12,000 miles, and biennial service as every 24 months or 24,000 miles, whichever occurs first. Road-test checks, brakes, steering, suspension, cooling, fuel, electrical wiring, air systems, transmission, transfer case, winches, special bodies, and other vehicle areas are incorporated into the PMCS material.

Troubleshooting is organized as a step-by-step path from a reported symptom toward tests, inspection points, and corrective action. Separate coverage is provided for mechanical faults, the electrical system, compressed-air and brake systems, STE/ICE testing, and CTIS. Examples of the kinds of faults addressed include no-crank and no-start conditions, poor engine performance, abnormal oil pressure, overheating, transmission and transfer-case problems, axle or wheel noise, steering faults, winch and PTO problems, air-brake malfunctions, electrical circuit problems, and M939A2 CTIS concerns. This makes the manual useful when the technician needs to isolate a fault before beginning a repair rather than replacing parts without a diagnostic path.

Individual maintenance tasks use a structured initial setup. Where applicable, a task identifies the models involved, tools and test equipment, materials or replacement parts, personnel requirements, references, required equipment condition, environmental conditions, and safety instructions before the procedure begins. Removal, cleaning, inspection, repair, adjustment, installation, and follow-on tasks are then presented in sequence. Illustrations are positioned to help identify component locations, attachments, and the relationship between parts during disassembly and installation.

System Information Included

The introductory system-operation material gives technicians context before they enter the repair procedures. It explains control, powertrain, electrical, compressed-air and brake, hydraulic, and CTIS operation. Subjects include starting and ether-start systems, accelerator controls, parking brake and steering operation, transmission and transfer-case controls, air intake, single- and dual-tank fuel systems, exhaust, cooling, engine lubrication, batteries and charging, indicators and warning circuits, trailer connections, service and spring brakes, auxiliary air-operated equipment, front and rear winch hydraulics, dump-body hydraulics, and the M936 wrecker crane hydraulic system.

The M939 series maintenance manual also provides equipment data and service values that support inspections and repairs. These include capacities, engine operating information, cooling-system data, electrical-system information, transmission and transfer-case data, pressure values, adjustment limits, inspection criteria, and torque values within the procedures. Model-specific notes distinguish M939/A1 components from M939A2 components where engines, filters, steering equipment, cooling arrangements, CTIS hardware, or other systems differ.

Chapters Covered

• Chapter 1 – Introduction
  • General Information
  • Equipment Description and Data
  • Principles of Operation
• Chapter 2 – Service and Troubleshooting Instructions
  • Repair Parts; Tools; Special Tools; Test, Measurement, and Diagnostic Equipment (TMDE); and Support Equipment
  • Service Upon Receipt
  • Unit Preventive Maintenance Checks and Services (PMCS)
  • General maintenance procedures for cleaning, inspection, repair, disassembly, and assembly
  • Unit Mechanical Troubleshooting
  • Electrical System Troubleshooting
  • Compressed Air and Brake System Troubleshooting
  • STE/ICE Troubleshooting
  • Central Tire Inflation System (CTIS) Troubleshooting

  IMAGES PREVIEW

  

  

  

• Chapter 3 – Unit Maintenance, Sections I-IX
  • Engine System Maintenance
  • Air Intake System Maintenance
  • Fuel System Maintenance
  • Exhaust System Maintenance
  • Cooling System Maintenance
  • Electrical System Maintenance
  • Transmission and Transfer Case Maintenance
  • Propeller Shafts, Axles, and Suspension System Maintenance
  • Compressed Air and Brake System Maintenance
• Alphabetical Index – task index for the material contained in Volume 1

Across these chapters, the document moves from vehicle identification and system theory into inspection and fault isolation, then into hands-on unit maintenance. That progression helps a technician understand how the M939/M939A1/M939A2 systems work, identify the likely source of a malfunction, prepare the vehicle and tools correctly, and carry out the applicable procedure with the specified checks and safety precautions.

File Details

• Manual type: Unit, Direct Support, and General Support Maintenance Manual – Volume 1 of 4
• Model series: M939, M939A1, M939A2 5-ton, 6×6 series trucks (diesel)
• Document number: TM 9-2320-272-24-1
• Air Force technical order: TO 36A12-1C-1155-2-1
• Date: 30 June 1998
• Language: English
• Pages: 1021
• File format: PDF

Repair and Maintain the M939 Series with the Correct Procedures

The M939 M939A1 M939A2 5-Ton 6×6 Truck Maintenance Manual Volume 1 – TM 9-2320-272-24-1 supports practical work ranging from scheduled inspection and fault diagnosis to component removal, replacement, adjustment, servicing, and system testing. It is especially useful when a job depends on the correct model application, equipment condition, test sequence, pressure or adjustment value, torque instruction, or follow-on check rather than a generic repair approach. Use it for engine and fuel-system work, cooling and electrical repairs, transmission and transfer-case maintenance, driveline and axle tasks, suspension service, compressed-air and brake work, and the diagnostic procedures that lead into those repairs.

After purchase, the manual is delivered as an instant PDF download with no shipping required. Open it on a computer, tablet, or phone, keep it available on any device that can read PDF files, and print the pages you need for workshop use.