A career as a diesel service technician or mechanic can offer
relatively high wages and the challenge of skilled repair work.
Opportunities are expected to be very good for persons who
complete formal training programs.
National certification is the recognized standard of achievement
for diesel service technicians and mechanics.
Nature of the Work
The diesel engine is the workhorse powering the Nation’s trucks
and buses because it delivers more power, is more efficient, and
is more durable than its gasoline-burning counterpart. Diesel-powered
engines also are becoming more prevalent in light vehicles, including
passenger vehicles, pickups, and other work trucks.
Diesel service technicians and mechanics, which includes 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. Other technicians repair diesel-powered passenger
automobiles, light trucks, or boats. (For information on technicians
and mechanics working primarily on gasoline-powered automobiles,
heavy vehicles, mobile equipment, or boats, see the Handbook
sections on automotive, and heavy vehicle, and mobile equipment;
and small engine service mechanics.)
Technicians who work for organizations that maintain their own
vehicles spend most of their time doing preventive maintenance,
to ensure that equipment will operate safely. These workers also
eliminate unnecessary wear on, and damage to, parts that could
result in costly breakdowns. During a routine maintenance check
on a vehicle, 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.
Increasingly, technicians must be versatile, in order to adapt
to customers’ needs and new technologies. It is common for technicians
to handle all kinds of repairs, from working on a vehicle’s electrical
system one day to 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 timing,
increasing the engine’s efficiency. Also, new emissions standards
are requiring mechanics to retrofit engines to comply with pollution
regulations. In modern shops, diesel service technicians use hand-held
or laptop computers to diagnose problems and adjust engine functions.
Because of continual advances in automotive technology, technicians
must regularly learn new techniques to repair vehicles.
Diesel service technicians use a variety of tools in their work,
including power tools, such as pneumatic wrenches, to 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 handtools—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.
In large shops, technicians generally receive their assignments
from shop supervisors or service managers. Most supervisors and
managers are experienced technicians who also assist in diagnosing
problems and maintaining quality standards. Technicians may work
as a team or be assisted by an apprentice or helper when doing
heavy work, such as removing engines and transmissions.
Diesel technicians usually work indoors, although they occasionally
make repairs to vehicles on the road. Diesel technicians may lift
heavy parts and tools, handle greasy and dirty parts, and stand
or lie in awkward positions to repair vehicles and equipment.
Minor cuts, burns, and bruises are common, although serious accidents
can usually be avoided if the shop is kept clean and orderly and
if safety procedures are followed. Technicians normally work in
well-lighted, heated, and ventilated areas; however, some shops
are drafty and noisy. Many employers provide lockers and shower
Training, Other Qualifications, and Advancement
Although many persons qualify for diesel service technician and
mechanic jobs through years of on-the-job training, authorities
on diesel engines recommend the completion of a formal diesel
engine training program. Employers prefer to hire graduates of
formal training programs because those workers often have a head
start in training and are able to advance quickly to the journey
level of diesel service.
Many community colleges and trade and vocational schools offer
programs in diesel repair. These programs, lasting 6 months to
2 years, lead to a certificate of completion or an associate degree.
Programs vary in the degree of hands-on training they provide
on equipment. Some offer about 30 hours per week on equipment,
whereas others offer more lab or classroom instruction. Training
provides a foundation in the latest diesel technology and instruction
in the service and repair of the vehicles and equipment that technicians
will encounter on the job. Training programs also improve the
skills needed to interpret technical manuals and to communicate
with coworkers and customers. In addition to the hands-on aspects
of the training, many institutions teach communication skills,
customer service, basic understanding of physics, and logical
thought. Increasingly, employers work closely with representatives
of training programs, providing instructors with the latest equipment,
techniques, and tools and offering jobs to graduates.
Whereas most employers prefer to hire persons who have completed
formal training programs, some technicians and mechanics continue
to learn their skills on the job. Unskilled beginners generally
are assigned tasks such as cleaning parts, fueling and lubricating
vehicles, and driving vehicles into and out of the shop. Beginners
usually are promoted to trainee positions as they gain experience
and as vacancies become available. In some shops, beginners with
experience in automobile service start as trainee technicians.
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 prove 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. The completion of a formal training program
speeds advancement to the journey level.
For unskilled entry-level jobs, employers usually look for applicants
who have mechanical aptitude and strong problem-solving skills
and who are at least 18 years of age and in good physical condition.
Nearly all employers require the completion of 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. 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.
Employers often send experienced technicians and mechanics to
special training classes conducted by manufacturers and vendors,
in which workers learn the latest technology and repair techniques.
Technicians constantly receive updated technical manuals and instructions
outlining changes in techniques and standards for repair. It is
essential for technicians to read, interpret, and comprehend service
manuals in order to keep abreast of engineering changes.
Voluntary certification by the National Institute for Automotive
Service Excellence (ASE) is the recognized industry credential
for diesel service technicians and mechanics. Diesel service technicians
may be certified as master medium/heavy truck technicians, master
school bus technicians, or master truck equipment technicians.
They may also be ASE-certified in specific areas of truck repair,
such as gasoline engines, drivetrains, brakes, suspension and
steering, electrical and electronic systems, or preventive maintenance
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 hands-on work experience. Two years of relevant formal
training from a high school, vocational or trade school, or community
or junior college program may be substituted for up to 1 year
of the work experience requirement. To remain certified, technicians
must be retested every 5 years. Retesting ensures that service
technicians and mechanics keep up with changing technology.
The most important work possessions of technicians and mechanics
are their handtools. Technicians usually provide their own tools,
and many experienced workers have thousands of dollars invested
in them. Employers typically furnish expensive power tools, computerized
engine analyzers, and other diagnostic equipment, but individual
workers ordinarily accumulate their own hand tools with experience.
Experienced diesel service technicians and mechanics with leadership
ability may advance to shop supervisor or service manager. Technicians
and mechanics with sales ability sometimes become sales representatives.
Some open their own repair shops.
Diesel service technicians and mechanics held about 270,000 jobs
in 2004. They were employed by almost every industry; in particular,
those that use trucks, buses, and equipment to haul, deliver,
and transport materials, goods, and people. The largest employer,
the truck transportation industry, employed nearly one out of
six diesel service technicians and mechanics. Slightly fewer were
employed by local governments, mainly to repair school buses,
waste removal trucks, and road equipment. About 1 out 10 was employed
by automotive and commercial equipment repair and maintenance
facilities. The rest were employed throughout the economy, including
construction, manufacturing, retail and wholesale trade, and automotive
leasing. 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.
Employment of diesel service technicians and mechanics is expected
to increase about as fast as the average for all occupations through
the year 2014. Besides openings resulting from employment growth,
opportunities will be created by the need to replace workers who
retire or transfer to other occupations.
Employment of diesel service technicians and mechanics is expected
to grow as freight transportation by truck increases. Additional
trucks will be needed to keep pace with the increasing volume
of freight shipped nationwide. Trucks also serve as intermediaries
for other forms of transportation, such as rail and air. Due to
the greater durability and economy of the diesel engine relative
to the gasoline engine, the number of buses, trucks, and passenger
vehicles that are powered by diesel engines is expected to increase.
While diesel engines are a more efficient and powerful option,
diesel engines tend to produce more pollutants than gasoline-powered
engines. As governments have applied emissions-lowering standards
to diesel engines, many older diesel engines must be retrofitted
to comply. These new emissions control systems, such as emissions
filters and catalysts, may create additional jobs for diesel service
technicians and mechanics.
Careers as diesel service technicians attract many because they
offer relatively high wages and the challenge of skilled repair
work. Opportunities should be very good for persons who complete
formal training in diesel mechanics at community and junior colleges
or vocational and technical schools. Applicants without formal
training may face stiffer competition for entry-level jobs.
Most persons entering this occupation can expect relatively steady
work, because changes in economic conditions have less of an effect
on the diesel repair business than on other sectors of the economy.
During a downturn in the economy, however, some employers may
lay off workers or be reluctant to hire new workers.
Median hourly earnings of bus and truck mechanics and diesel
engine specialists, including incentive pay, were $17.20 in May
2004. The middle 50 percent earned between $13.73 and $21.13 an
hour. The lowest 10 percent earned less than $11.19, and the highest
10 percent earned more than $25.67 an hour. Median hourly earnings
in the industries employing the largest numbers of bus and truck
mechanics and diesel engine specialists in May 2004 were as follows:
Local government, excluding schools
Motor vehicle and motor vehicle parts and
supplies merchant wholesalers
Automotive repair and maintenance
General freight trucking
Elementary and secondary schools
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.
The majority of 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, either to
perform repairs and routine service in a more timely fashion or
as a convenience to customers. Those technicians employed by truck
and bus firms providing service around the clock may work evenings,
nights, and weekends, usually at a higher rate of pay than those
working traditional hours.
Many 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.
Diesel service technicians and mechanics repair trucks, buses,
and other diesel-powered equipment. Related technician and mechanic
occupations include aircraft and avionics equipment mechanics
and service technicians, automotive service technicians and mechanics,
heavy vehicle and mobile equipment service technicians and mechanics,
and small engine mechanics.
Sources of Additional Information
More details about work opportunities for diesel service technicians
and mechanics may be obtained from local employers such as trucking
companies, truck dealers, or buslines; locals of the unions previously
mentioned; and local offices of your State employment service.
Local State employment service offices also may have information
about training programs. State boards of postsecondary career
schools have information on licensed schools with training programs
for diesel service technicians and mechanics.
For general information about a career as a diesel service technician
or mechanic, write:
Association of Diesel Specialists, 10 Laboratory Dr., PO Box
13966, Research Triangle Park, NC 27709. Internet: http://www.diesel.org/
Information on how to become a certified diesel technician of
medium to heavy-duty vehicles or a certified bus technician is
National Institute for Automotive Service Excellence (ASE),
101 Blue Seal Dr. SE, Suite 101, Leesburg, VA 20175. Internet:
For a directory of accredited private trade and technical schools
with training programs for diesel service technicians and mechanics,
Accrediting Commission of Career Schools and Colleges of Technology,
2101 Wilson Blvd., Suite 302, Arlington, VA 22201. Internet:
National Automotive Technicians Education Foundation, 101
Blue Seal Dr., SE., Suite 101, Leesburg, VA 20175. Internet:
Bureau of Labor Statistics, U.S. Department
of Labor, Occupational Outlook Handbook,