iii Preface Heavy Equipment Power Trains and Systems was developed to educate students who are planning a career in the off-highway industry, especially construction and agricultural equipment. However, this text will empower students working in other heavy equipment power train fields, like forestry or mining, and is appropriate for students who are pursu- ing a certificate, associate’s degree, bachelor’s degree, or master’s degree. The author and publisher proudly support the mission of the AED Foundation, which encourages continuous learning, provides educational opportunities for today’s employ- ees, and improves the availability and quality of tomorrow’s equipment industry techni- cians. The contents of this text have been carefully correlated to the Power Trains section and key areas of the Safety and Hydraulics/Hydrostatics sections of AED’s “Standards for Construction Equipment Technology.” This textbook includes traditional power train content such as safety, overhead lift- ing, belts, chains, gearing, manual transmissions, planetary transmissions, countershaft transmissions, powershift and automatic transmissions, torque converters, hydrostatic drives, brake systems, suspensions, tires, undercarriages, track steering, wheeled steering systems, and electric drives. In addition, the book is especially unique in providing an in- depth explanation of late-model continuously variable transmissions. The text provides fundamental instruction on hydrostatic transmissions with the goal of having students fully comprehend the systems rather than needing to rely on discrete (or limited) troubleshooting charts. Students will also gain instruction in hydraulic diagnos- tic principles such as how to tap into the system, what tools are available, how to properly use those tools, and how to perform the tests safely. Heavy Equipment Power Trains and Systems, provides students the necessary foun- dational building blocks, equipping them for a bright future in off-highway power train technology. The book includes over 1000 images comprised of multicolor line art, cross- sectional drawings, photographs, and 3-D images. The book includes review questions, case studies, and helpful techniques for diagnosing power trains.