Diesel service technicians and mechanics, also known as bus and truck mechanics and diesel engine specialists, repair and maintain the diesel engines that power transportation equipment such as heavy trucks, buses, and locomotives. Some diesel technicians and mechanics also work on heavy vehicles and mobile equipment, including bulldozers, cranes, road graders, farm tractors, and combines. A small number of technicians repair diesel-powered passenger automobiles, light trucks, or boats.
Diesel service technicians and mechanics held about 267,000 jobs in 2002. About 20 percent serviced buses, trucks, and other diesel-powered equipment for customers of automotive repair and maintenance shops, motor vehicle and parts wholesalers, or automotive equipment rental and leasing agencies. About 19 percent maintained the buses, trucks, and other equipment of bus lines, public transit companies, school systems, or State and local governments, and another 17 percent worked for freight trucking companies. The remaining technicians maintained vehicles and other equipment for manufacturing, construction, or other companies. A relatively small number were self-employed. Nearly every section of the country employs diesel service technicians and mechanics, although most work in towns and cities where trucking companies, bus lines, and other fleet owners have large operations.