Career Guides

Career Guide for Diesel Mechanics

A diesel engine mechanic works on diesel based vehicles such as a large truck, train, or bus. Many commercial fleets of vehicles are driven by diesel engines due to the more efficient fuel burning as compared to gasoline engines.

In this free career guide, you will learn how to have a successful career as a diesel mechanic.

Diesel Mechanic Summary

  • In addition to high school course offerings in automotive repair and electronics, programs in diesel engine repair are offered by many community colleges and trade and technical schools.
  • Opportunities are expected to be very good for people who complete formal training programs; applicants without formal training will face competition for jobs.
  • National certification, the recognized standard of achievement, enhances a diesel service technician’s advancement opportunities.

Working as a Diesel Mechanic

Diesel-powered engines are more efficient and durable than their gasoline-burning counterparts. These powerful engines are standard in our Nation’s trucks, locomotives, and buses and are becoming more prevalent in light vehicles, including passenger vehicles, pickups, and other work trucks.

Diesel service technicians and mechanics, including bus and truck mechanics and diesel engine specialists, repair and maintain the diesel engines that power transportation equipment. Other diesel technicians and mechanics work on other heavy vehicles and mobile equipment, including bulldozers, cranes, road graders, farm tractors, and combines. Others repair diesel-powered passenger automobiles, light trucks, or boats.

Increasingly, diesel technicians must be versatile enough to adapt to customers’ needs and to new technologies. It is common for technicians to handle all kinds of repairs, working on a vehicle’s electrical system one day and doing major engine repairs the next. Diesel maintenance is becoming increasingly complex, as more electronic components are used to control the operation of an engine. For example, microprocessors now regulate and manage fuel injection and engine timing, increasing the engine’s efficiency. Also, new emissions standards may require mechanics to retrofit engines with emissions control systems, such as emission filters and catalysts, to comply with pollution regulations. In modern shops, diesel service technicians use hand-held or laptop computers to diagnose problems and adjust engine functions.

Technicians who work for organizations that maintain their own vehicles spend most of their time doing preventive maintenance. During a routine maintenance check, technicians follow a checklist that includes inspecting brake systems, steering mechanisms, wheel bearings, and other important parts. Following inspection, technicians repair or adjust parts that do not work properly or remove and replace parts that cannot be fixed.

Diesel service technicians use a variety of tools in their work, including power tools, such as pneumatic wrenches that remove bolts quickly; machine tools, such as lathes and grinding machines to rebuild brakes; welding and flame-cutting equipment to remove and repair exhaust systems; and jacks and hoists to lift and move large parts. Common hand tools—screwdrivers, pliers, and wrenches—are used to work on small parts and get at hard-to-reach places. Diesel service technicians and mechanics also use a variety of computerized testing equipment to pinpoint and analyze malfunctions in electrical systems and engines. Employers typically furnish expensive power tools, computerized engine analyzers, and other diagnostic equipment, but workers usually accumulate their own hand tools over time.

Work environment. Technicians normally work in well-lighted and ventilated areas. However, some shops are drafty and noisy. Many employers provide lockers and shower facilities. Diesel technicians usually work indoors, although they occasionally repair vehicles on the road or at the jobsite. Diesel technicians may lift heavy parts and tools, handle greasy and dirty parts, and stand or lie in awkward positions while making repairs. Minor cuts, burns, and bruises are common, although serious accidents can usually be avoided when safety procedures are followed. Technicians may work as a team or be assisted by an apprentice or helper when doing heavy work, such as removing engines and transmissions.

Most service technicians work a standard 40-hour week, although some work longer hours, particularly if they are self-employed. A growing number of shops have expanded their hours to speed repairs and offer more convenience to customers. Some truck and bus firms provide maintenance and repair service around the clock and on weekends.

Training, Other Qualifications, and Advancement

Employers prefer to hire graduates of formal training programs because those workers are able to advance quickly to the journey level of diesel service. Other workers who learn diesel engine repair through on-the-job training need 3 to 4 years of experience before becoming journey-level technicians.

Education and training. High school courses in automotive repair, electronics, English, mathematics, and physics provide a strong educational background for a career as a diesel service technician or mechanic. Many mechanics have additional training after high school.

A large number of community colleges and trade and vocational schools offer programs in diesel engine repair. These programs usually last from 6 months to 2 years and may lead to a certificate of completion or an associate degree. Some offer about 30 hours per week of hands-on training with equipment; others offer more lab or classroom instruction. Formal training provides a foundation in the latest diesel technology and instruction in the service and repair of the equipment that technicians will encounter on the job. Training programs also teach technicians to interpret technical manuals and to communicate well with co-workers and customers. Increasingly, employers work closely with representatives of educational programs, providing instructors with the latest equipment, techniques, and tools and offering jobs to graduates.

Although formal training programs lead to the best prospects, some technicians and mechanics learn through on-the-job training. Unskilled beginners generally are assigned tasks such as cleaning parts, fueling and lubricating vehicles, and driving vehicles into and out of the shop. Beginners are usually promoted to trainee positions as they gain experience and as vacancies become available.

After a few months’ experience, most trainees can perform routine service tasks and make minor repairs. These workers advance to increasingly difficult jobs as they improve their ability and competence. After technicians master the repair and service of diesel engines, they learn to work on related components, such as brakes, transmissions, and electrical systems. Generally, technicians with at least 3 to 4 years of on-the-job experience will qualify as journey-level diesel technicians.

Employers often send experienced technicians and mechanics to special training classes conducted by manufacturers and vendors, in which workers learn about the latest technology and repair techniques.

Other qualifications. Employers usually look for applicants who have mechanical aptitude and strong problem-solving skills and who are at least 18 years old and in good physical condition. Technicians need a State commercial driver’s license to test-drive trucks or buses on public roads. Many companies also require applicants to pass a drug test. Practical experience in automobile repair at an automotive service station, in the Armed Forces, or as a hobby is valuable as well.

Certification and advancement. Experienced diesel service technicians and mechanics with leadership ability may advance to shop supervisor or service manager, and some open their own repair shops. Technicians and mechanics with sales ability sometimes become sales representatives.

Although national certification is not required for employment, many diesel engine technicians and mechanics find that it increases their ability to advance. Certification by the National Institute for Automotive Service Excellence (ASE) is the recognized industry credential for diesel and other automotive service technicians and mechanics. Diesel service technicians may be certified in specific areas of truck repair, such as drivetrains, brakes, suspension and steering, electrical and electronic systems, or preventive maintenance and inspection. For certification in each area, a technician must pass one or more of the ASE-administered exams and present proof of 2 years of relevant work experience. To become what’s known as a master technician, all the tests in a given series must be passed. To remain certified, technicians must be retested every 5 years.

Employment as a Diesel Engine Mechanic

Diesel service technicians and mechanics held about 263,100 jobs in 2008. These workers were employed in almost every industry, particularly those that use trucks, buses, and equipment to haul, deliver, and transport materials, goods, and people. The largest employer, the truck transportation industry, employed about 17 percent of diesel service technicians and mechanics. About 8 percent were employed by automotive repair and maintenance facilities. The rest were employed throughout the economy, including construction, manufacturing, retail and wholesale trade, and automotive leasing. About 6 percent were self-employed. Nearly every area of the country employs diesel service technicians and mechanics, although most work is found in towns and cities where trucking companies, bus lines, and other fleet owners have large operations.

Job Outlook

The number of jobs for diesel service technicians and mechanics is projected to grow slower than the average for all occupations. Opportunities should be very good for people who complete formal training in diesel mechanics; applicants without formal training will face competition for jobs.

Employment change. Employment of diesel service technicians and mechanics is expected to grow by 6 percent from 2008 to 2018, slower than the average for all occupations. The diesel engine, because of its durability and fuel efficiency, is the preferred engine for heavy-duty trucks, buses, and other large vehicles. As more freight is shipped across the country, additional trucks, and corresponding truck repairers, will be needed. Despite this trend, the increasing durability of new vehicles will limit the need for additional workers. Most new jobs will continue to be in the freight trucking and automotive repair and maintenance industries. Beyond the growth in the number of vehicles that need to be serviced, there will be additional demand for diesel engines mechanics to retrofit and modernize existing vehicles to comply with environmental regulations.

Due to higher fuel efficiency requirements for automakers, diesel engines are expected to be used in a small but increasing number of cars and light trucks. This will create additional jobs for diesel service technicians, specifically in the automotive repair and maintenance and automobile dealer industries.

Job prospects. People who enter diesel engine repair will find favorable opportunities, especially as the need to replace workers who retire increases over the next decade. Opportunities should be very good for people with strong technical skills and who complete formal training in diesel mechanics at community colleges or vocational schools. Applicants without formal training will face competition for jobs.

Projections Data

Projections data from the National Employment Matrix
Occupational Title SOC Code Employment, 2008 Projected
Employment, 2018
Change,
2008-18
Number Percent
Bus and truck mechanics and diesel engine specialists 49-3031 263,100 278,000 14,900 6
NOTE: Data in this table are rounded.

Earnings for Diesel Mechanics

Median hourly wages of bus and truck mechanics and diesel engine specialists, including incentive pay, were $18.94 in May 2008. The middle 50 percent earned between $15.25 and $23.58 an hour. The lowest 10 percent earned less than $12.50, and the highest 10 percent earned more than $28.41 an hour. Median hourly wages in the industries employing the largest numbers of bus and truck mechanics and diesel engine specialists in May 2008 were as follows:

Automotive equipment rental and leasing $19.27
Motor vehicle and motor vehicle parts and supplies merchant wholesalers 19.04
General freight trucking 18.00
Automotive repair and maintenance 17.83
Specialized freight trucking 16.99

Because many experienced technicians employed by truck fleet dealers and independent repair shops receive a commission related to the labor cost charged to the customer, weekly earnings depend on the amount of work completed. Beginners usually earn from 50 to 75 percent of the rate of skilled workers and receive increases as they become more skilled.

About 23 percent of diesel service technicians and mechanics are members of labor unions, including the International Association of Machinists and Aerospace Workers; the Amalgamated Transit Union; the International Union, United Automobile, Aerospace and Agricultural Implement Workers of America; the Transport Workers Union of America; the Sheet Metal Workers’ International Association; and the International Brotherhood of Teamsters. Labor unions may provide additional benefits for their members.