Fundamentals of Truck and Off-Highway Transmission Systems

This course will develop a basic understanding of the fundamentals of operation and explain the current state-of-the-art design of the modern transmission designs. Transmission systems in current production will be used as a practical example throughout the seminar. Two basic product areas of truck and off-highway transmission systems will be reviewed: Planetary Automatic Transmissions, and Power-Shifted Transmissions.

The functional requirements of the "current" market and the operational needs of its drivers will drive the course. Course material will be presented in the chronological order in which it was introduced into the marketplace. This order is shown through the requirements of " new" functionality by the marketplace at the time it was introduced. The design advances that satisfied these requirements will be discussed and used to show design progression through to the current state of design.

This "current state-of-the-art" design schematic will then be used to show the driving forces behind the next evolutionary step in the development of future designs of transmission systems. All aspects of current designs will be reviewed in depth; the components used, how they operate and the interrelation of all components. All functional modes of the major components and sub-systems will be discussed and explained to the audience. Based on this working knowledge of transmission components and systems, attendees will work through design specifications, functional modes and considerations of reliability and life for each major sub-system in a transmission system.

The seminar will conclude with a brief discussion of the future of transmission systems and what functional requirements are likely to be expected by the users of the next generation vehicles within this market.

What Will You Learn

By attending this seminar, you will be able to:
  • Identify the major components and system functions in a modern truck or off-highway transmission system
  • Compute powerflow, relative rotational speeds of various components, and the functional relationships that exists between these components
  • Specify the size of a truck or off-highway transmission, select the numbers of speed ranges and ratios for each, and assess system efficiency
  • Explain the operational aspects and design principles of each of the major components and sub-systems of a transmission
  • Describe the operational parameters and inter-relationships of each of the sub-systems within the truck transmission
  • Summarize basic design synthesis and analysis techniques for each of the major components and sub-systems of a transmission
  • Discuss the direction of new truck and off-highway equipment transmission designs

Is This Course For You

The intended audience for this seminar is powertrain design engineers, designers, engineering directors and managers, component suppliers, platform powertrain test and development specialists, and those involved in the application, design and discussion of engines.

The seminar will appeal to anyone who is interested in truck or off-highway vehicle operation and design.

Materials Provided

This data is not available at this time

Course Requirements

This data is not available at this time


  • Theory of Operation of a Basic Transmission
    • Basic transmission layout
    • Main components
    • Common configurations/transmission types
  • Development of the "Automatic" Transmission
  • Major Components of a Modern Automatic Transmission
    • Torque converter
    • Planetary gearsets
    • Clutch packs and bands
    • Powerflow
  • Functionality
    • Torque converter operation
    • Gear systems
    • Gear design considerations
  • Type
  • Layout
  • NVH (Noise, Vibration and Harshness)
  • Planetary powerflow
    • Common gear arrangements and standard design configurations
  • Clutches and bands
    • One-way/over-riding clutches
  • Comparisons to Power-Shift transmissions
  • Operational characteristics of power-shift transmissions
  • Components and typical layouts
  • Clutch packs
  • Shift systems
  • Application and duty cycle consideration
  • Design considerations for Over-The-Road Transmissions
  • Process to select the number of speed ranges
  • Select approximate gear ratios for each speed range
  • Calculate losses and efficiencies
  • Power-flow optimization
  • Duty cycle considerations
  • Design for reliability and life
  • Design considerations for Off-Highway transmissions
  • Process to select the number of speed ranges
  • Select approximate gear ratios for each speed range
  • Calculate losses and efficiencies
  • Design information content of engine curves
  • Duty cycle considerations
  • Design for service, repair and "rebuildability"
  • Future direction of technologies