Fundamentals of Modern Vehicle Transmissions

Starting with a look at the transmission's primary function -- to couple the engine to the driveline and provide torque ratios between the two -- this updated and expanded seminar covers the latest transmission systems designed to achieve the most efficient engine operation. Current designs, the components and sub-systems used, their functional modes, how they operate, and the inter-relationships will be discussed.

A manual transmission display will be used to explain ratios and how they function within the driveline. Automatic transmission design will illustrate the concept of automatic control and hydro-mechanic decision theory and implementation. Attendees will have the opportunity to supplement these theoretical concepts with practical, "hands-on" experience using the various transmission models and components provided. Mechatronics, toroidal transmission functions, and the future of the automatic transmission will also be discussed.

Continuously Variable Transmission (CVT) systems, which represent a fundamental shift in the way power is transmitted from the primary source to the remainder of the driveline will be the focus of in-depth coverage on the third day of this seminar.

What Will You Learn

By attending this seminar, you will be able to:
  • Explain the development, operational aspects and design principles of passenger vehicle and light truck transmission systems, their major components and sub-systems
  • Describe the operational parameters and inter-relationships of each of the sub-systems
  • Apply basic design synthesis and analysis techniques for each of the major components and sub-systems
  • Compare and contrast 'stepless' to 'stepped' transmission technology
  • Identify and describe the function and operation of all major components and sub-systems by participating in hands-on demonstrations
  • Recognize the limitations, technological trends, and potential new products under consideration
  • Summarize the direction of new passenger car transmission designs and systems

Is This Course For You

This seminar is intended for anyone not familiar with the operational theories or functional principles of modern vehicle transmission systems. As the material covered is targeted at a number of design and engineering disciplines, attendees should have a minimum of two years design experience in the automotive powertrain field, or preferably a B.S. in engineering or related field.

Also available as an SAE On Demand Course! 
Fundamentals of Modern Vehicle Transmissions (PD730419)

Materials Provided

This data is not available at this time

Course Requirements

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  • Overview of Mechanical Power Transmission in a Passenger Vehicle and Light Truck -- Manual transmission; automatic transmission; continuously variable transmission (CVT)
  • Theory, Function and Operation of Manual Transmission -- Design; main components; common configurations
  • Vehicle Powertrain Requirements and Specifications Assessment
  • Shift Strategy Analysis and Control System Implementation
  • Components and Sub-systems -- Shifters, clutches, synchronizers, gears, shafts
  • Basic Gear Theory and Application Development
  • Powerflow Analysis
  • Synchronizer Operation and Analysis
  • Lubrication and Cooling Requirements Review


  • Development and Layout of the "Automatic" Transmission -- Front-wheel drive; rear-wheel drive; four-wheel drive
  • Functionality -- Torque converter operation; gear systems; gear design considerations; type; layout; NVH (Noise, Vibration and Harshness); epicyclic powerflow
  • Extension of Gear Theory to Epicyclic Gear-trains
  • Design and Operation of Clutches and Bands
  • Application of One-Way/Over-Riding Clutches
  • Powerflow Analysis of Torque Converters, Epicyclic Gear Sets
  • Review of Shift Strategy
  • Implementation of Shift Strategy Through Hydro-Mechanical Control Systems
  • Simple Shift Model Analysis
  • Lubrication and Cooling Requirements Review


  • CVT Design and Operation -- Theory and function; typical layout; main components
  • Technological Development of the CVT
  • Basic Theory of Friction Drives
  • Toroidal Drive Technology -- Theory of operation; main components; benefits and limitation of the technology
  • Functionality and Characteristics of CVT Components, Sub-systems -- Gearbox housing; variators; forward clutch; converter housing; input shaft; selector shift valve; differential; output shaft; mechatronic control unit; belt/push chain
  • CVT Power-Flow -- Torque converter; primary variator; secondary variator; output shaft
  • Mechatronics -- Theory and operation; general implementation; CVT application
  • CVT Manufacturing -- Considerations; major manufacturers; future CVT development
  • Future Technologies -- "Manualized" automatics, automated manuals; DCT, SSCT, DSCT