California Occupational Guides

Summary Guide  (Printer Friendly)
Detailed Guide   (Printer Friendly)
   Detailed Report-Jump to: 
         Top of Page
         What Would I Do?
         Wages and Benefits
         Job Outlook
         How Do I Qualify?
         What Employers Say...
Job Search Tips

I want to: 
   Search by Topic
   Search by Keyword


Change Your Area:

Select your county from the list:

Change Occupation:

1. Enter a keyword and click the "GO!" button:

2. Select an occupation from the results listed
below and click the "Get Information" button.

Detailed Guide for

   Bus and Truck Mechanics and Diesel Engine Specialists in San Diego County

May also be called: Diesel Mechanics; Farm Equipment Engine Mechanics; Fleet Mechanics; Medium and Heavy Truck Mechanics; Tractor Trailer Mechanics

What Would I Do?

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.

Bus and Truck Mechanics and Diesel Engine Specialists repair and maintain heavy duty vehicles used in transportation and elsewhere. As bus fleets convert to technology for cleaner emissions, Mechanics must maintain engines running on alternate fuel, such as compressed natural gas, liquefied natural gas, or propane. Some work mostly on diesel engines or equipment such as farm machines, ships, locomotives, and compressors and pumps used in oil well drilling and irrigation. In construction, Mechanics work on equipment, such as cranes, power shovels, bulldozers, paving machines, earthmovers, and graders. Others repair diesel-powered passenger vehicles or vehicles powered by biodiesel, hybrid-electric, fuel cells, gasoline, or propane.

Mechanics’ duties vary with shop policy as well as the type of equipment they work on. In engine-building shops, some Mechanics repair and adjust engines to restore them to good working order. Others retrofit or replace engines and exhaust systems to reduce emissions to meet environmental regulations. Mechanics who work in garages or heavy equipment shops usually have more varied duties. They may work on engines, transmissions, differentials, chassis, brakes, steering gears, and front ends for both conventional and alternative fuel vehicles. They also work on motors, compressors, and hydraulic and electrical systems. They dismantle, clean, repair, refit, assemble, and test the equipment according to manufacturers’ manuals and specifications.

Tools and Technology
Mechanics’ work has become increasingly complex as vehicles are using alternative fuels and more electronic components. To perform their duties, Mechanics use a variety of tools, such as gauges; hand-held or laptop computers; electric, pneumatic, hydraulic, and computer-based diagnostic tools. They also use oscilloscopes, voltmeters, ammeters, ohmmeters, frequency and special generators, and common hand tools like hammers. As technologies become more advanced in alternative fuel vehicles, additional tools and test equipment may be required.

Green Economy(1)
Bus and Truck Mechanics and Diesel Engine Specialists will play an important role in the emerging green economy. They will assist in reducing the environmental impacts of vehicle emissions while increasing fuel efficiency.

Important Tasks and Related Skills

Each task below is matched to a sample skill required to carry out the task.

View the skill definitions
TaskSkill Used in this Task
Use hand tools such as screwdrivers, pliers, wrenches, pressure gauges, and precision instruments, as well as power tools such as pneumatic wrenches, lathes, welding equipment, and jacks and hoists.Mechanical
Perform routine maintenance such as changing oil, checking batteries, and lubricating equipment and machinery.Equipment Maintenance
Adjust and reline brakes, align wheels, tighten bolts and screws, and reassemble equipment.Multilimb Coordination
Raise trucks, buses, and heavy parts or equipment using hydraulic jacks or hoists.Manual Dexterity
Test drive trucks and buses to diagnose malfunctions or to ensure that they are working properly.Troubleshooting
Inspect, test, and listen to defective equipment to diagnose malfunctions, using test instruments such as handheld computers, motor analyzers, chassis charts, and pressure gauges.Equipment Selection
Examine and adjust protective guards, loose bolts, and specified safety devices.Near Vision
Inspect and verify dimensions and clearances of parts to ensure conformance to factory specifications.Visualization
Inspect, test, and listen to defective equipment to diagnose malfunctions, using test instruments such as handheld computers, motor analyzers, chassis charts, and pressure gauges.Judgment and Decision Making
Source: U.S. Department of Labor Occupational Information Network (O*NET)

Working Conditions

Bus and Truck Mechanics and Diesel Engine Specialists normally work in well-lit, ventilated shops that can be drafty, greasy, and noisy. Some Mechanics work outdoors in all kinds of weather and may need to travel to repair vehicles on the road. Mechanics may lift heavy parts and tools, handle greasy and dirty parts, and stand or lie in awkward positions while making repairs. They may work as a team or be assisted by an apprentice or helper when doing heavy work, such as removing engines. Minor cuts, burns, and bruises are common, although serious accidents can usually be avoided when safety procedures are followed. Mechanics who work with alternative fuel vehicles must be aware of the different safety procedures. Mechanics are expected to have their own tools and precision instruments which can cost over $1,000. Employers may provide specialized tools and power equipment.

Most Mechanics 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 resulting in more varied work schedules, such as flexible hours or shift work. This is especially true for employees of bus and truck firms, which need Mechanics around the clock.

Mechanics may join unions such as the Amalgamated Transit Union, the Transport Workers of America, the Operating Engineers Union, or the International Brotherhood of Teamsters.

Will This Job Fit Me?

This job may appeal to those who enjoy practical, hands-on problems and solutions, in addition to working with tools and machinery.

What Wages and Benefits Can I Expect?

Bus and Truck Mechanics and Diesel Engine Specialists who are employed on commission receive earnings that vary with the amount of work completed.


The median wage in 2017 for Bus and Truck Mechanics in California was $52,745 annually, or $25.36 hourly. The median wage for Bus and Truck Mechanics in San Diego County was $51,174 annually, or $24.60 hourly. The median is the point at which half of the workers earn more and half earn less.

Change to Hourly Wages
Annual Wages for 2017Low
(25th percentile)
(50th percentile)
(75th percentile)
San Diego County$38,221$51,174$62,637
Source: EDD/LMID Occupational Employment Statistics Survey, 2017 Wages do not reflect self-employment.
View Wages for All Areas


Common benefits for Mechanics include vacation and sick leave, medical, dental, vision, and life insurance, as well as retirement packages. Mechanics may receive additional benefits from membership in unions.

What is the Job Outlook?

Over the long run, Mechanics will be required as additional trucks are needed to keep pace with the increasing volume of freight shipped nationwide. In addition, the use of vehicles powered by alternative fuels is expected to increase in buses, trucks, and passenger vehicles because they are more efficient and environmentally friendly.(1) However, like many occupations, employment may be sensitive to the fluctuations in the economy.

(1)This workforce solution was funded by a grant awarded by the U.S. Department of Labor's Employment and Training Administration. The solution was created by the grantee and does not necessarily reflect the official position of the U.S. Department of Labor. The Department of Labor makes no guarantees, warranties, or assurances of any kind, express or implied, with respect to such information, including any information on linked sites and including, but not limited to, accuracy of the information or its completeness, timeliness, usefulness, adequacy, continued availability, or ownership. This solution is copyrighted by the institution that created it. Internal use by an organization and/or personal use by an individual for non-commercial purposes is permissible. All other uses require the prior authorization of the copyright owner.

Projections of Employment

In California, the number of Bus and Truck Mechanics is expected to grow faster than average growth rate for all occupations. Jobs for Bus and Truck Mechanics are expected to increase by 21.3 percent, or 4,700 jobs between 2014 and 2024.

In San Diego County, the number of Bus and Truck Mechanics is expected to grow faster than average growth rate for all occupations. Jobs for Bus and Truck Mechanics are expected to increase by 21.1 percent, or 360 jobs between 2014 and 2024.

Estimated Employment and Projected Growth
Bus and Truck Mechanics
Geographic Area
(Estimated Year-Projected Year)
Additional Openings
Due to Net
San Diego County
Source: EDD/LMID Projections of Employment by Occupation
View Projected Growth for All Areas

Annual Job Openings

In California, an average of 470 new job openings per year is expected for Bus and Truck Mechanics, plus an additional 380 job openings due to net replacement needs, resulting in a total of 850 job openings.

In San Diego County, an average of 36 new job openings per year is expected for Bus and Truck Mechanics, plus an additional 29 job openings due to net replacement needs, resulting in a total of 65 job openings.

Estimated Average Annual Job Openings
Bus and Truck Mechanics
Geographic Area
(Estimated Year-
Projected Year)
Jobs From GrowthJobs Due to
Net Replacements
Total Annual
Job Openings
San Diego County
Source: EDD/LMID Projections of Employment by Occupation
View Data for All Areas

How Do I Qualify?

Education, Training, and Other Requirements

Employers prefer to hire high school graduates who have a mechanical aptitude, are at least 18 years old, and are in good physical condition. Mechanics need a State commercial driver license to test-drive trucks or buses on public roads. Many community colleges and trade or vocational schools offer programs lasting from six months to two years leading to a certificate or associate degree. Formal training provides a foundation in the latest technology and instruction in the service and repair of equipment found on the job. Training programs also teach how to interpret technical manuals. Some programs offer more hands-on training with equipment, while others offer more lab or classroom instruction. Additional programs offer specific training for alternative fuel technologies. Many employers require applicants to pass a physical exam, drug test, and background check. Practical experience in automobile repair at an automotive service station, in the Armed Forces, or as a hobby is valuable as well.


Some Mechanics learn through on-the-job training. Entry-level Mechanics generally are assigned tasks such as cleaning parts and lubricating vehicles. They are usually promoted to trainee positions as they gain experience and vacancies become available. After a few months experience, most trainees can perform routine service tasks and make minor repairs. Over a three to four year period, they advance to increasingly difficult jobs as they prove their competence to work at a journey level mastering repair and service of diesel engines and related components, such as brakes or electrical systems.

Early Career Planning

High school students interested in Mechanic careers may take courses in auto shop, machine shop, electronics, English, mathematics, and physics. Good reading and math skills are needed for studying technical manuals.

Apprenticeship and Work Study Programs

A formal four-year apprenticeship is one way to become a Mechanic. Many apprenticeship programs require a high school diploma or equivalent. Most applicants must seek employment from participating employers after meeting the qualifications to enter the Mechanic apprenticeship program.  For more information on apprenticeship programs currently available, visit the State of California's Department of Industrial Relations, Division of Apprenticeship Standards Web site.

Training programs are also available through Regional Occupational Programs (ROP). To find an ROP program near you, go to the California Association of Regional Occupational Centers and Programs Web site.

Continuing Education

Mechanics need to keep up with the latest developments in technology. To keep current, they can take advantage of training programs offered by professional associations or take classes at local community colleges or trade schools. Employers often send experienced Mechanics to training classes conducted by manufacturers and vendors to learn the latest technology and repair techniques.


Certification is not required to work in California, but it can improve a Mechanic’s opportunities to advance and is required by some employers. The National Institute for Automotive Service Excellence (ASE) offers master medium and heavy truck technician, master school bus technician, and master truck equipment technician certificates. They also certify for specific categories of truck repair, such as drivetrains, brakes, suspension, electrical and electronic systems, and preventive maintenance and inspection. To obtain one of these five-year renewable certificates, applicants must pass one or more exams and present proof of two years relevant work experience. Formal training may be substituted for experience. For Mechanics who have already obtained certifications, ASE also offers certification for Electronic Diesel Engine Diagnosis Specialist. This five-year certificate is renewed by maintaining certificates in other test categories and taking an exam. For more information, go to the U.S. Department of Labor's Career InfoNet Web site and scroll down to "Career Tools." Click on "Certification Finder" and follow the instructions to locate certification programs.

Where Can I Find Training?

There are two ways to search for training information:

  • Search by Field of Study to find what programs are available and what schools offer those programs. You may use keywords such as: Diesel, Medium and Heavy Truck Technology, Automotive Mechanics, Automotive Services, Heavy Equipment Technology, and Agricultural Mechanics.
  • Search by Training Provider to find schools by name, type of school, or location.

Contact the schools you are interested in to learn about the classes available, tuition and fees, and any prerequisite course work.

Where Would I Work?

Bus and Truck Mechanics and Diesel Engine Specialists work in a variety of industries. The largest industries employing Bus and Truck Mechanics are as follows:

Industry TitlePercent of Total Employment for Occupation in California
Local Government14.2%
Automotive Repair and Maintenance10.9%
Motor Vehicle/Part Merchant Wholesalers8.1%
General Freight Trucking7.5%
Automotive Equipment Rental and Leasing6.0%
Source: EDD/LMID Staffing Patterns

Finding a Job

Direct application to employers remains one of the most effective job search methods. Employers frequently advertise job opportunities on the Internet and in newspapers as well. Unions may offer job search assistance though their Web sites or hiring halls. Graduates of formal training programs may also obtain job leads from the school placement office.  Online job opening systems include JobCentral at and CalJOBSSM at

To find your nearest One-Stop Career Center, go to Service Locator. View the helpful job search tips for more resources. (requires Adobe Reader).

Yellow Page Headings

You can focus your local job search by checking employers listed online or in your local telephone directory. Below are some suggested headings where you might find employers of Bus and Truck Mechanics.

  • Automotive Repair
  • Bus
  • Diesel
  • Freight
  • Government Offices
  • Machinery Repair and Maintenance
  • Railroad Companies
  • Transportation
  • Trucking

Find Possible Employers

To locate a list of employers in your area, go to "Find Employers" on the Labor Market Information Web site:

  • Select one of the top industries that employ the occupation. This will give you a list of employers in that industry in your area.
  • Click on "View Filter Selections" to limit your list to specific cities or employer size.
  • Click on an employer for the street address, telephone number, size of business, Web site, etc.
  • Contact the employer for possible employment.

Where Could This Job Lead?

Experienced Mechanics with leadership ability may advance to shop supervisor, fleet manager, or service manager. Some may open their own repair shops. Those with sales ability sometimes become sales representatives.

Related Occupations

Below is a list of occupations related to Bus and Truck Mechanics with links to more information.

Automotive Service Technicians and MechanicsGuide
Electric Motor, Power Tool, and Related RepairersProfile
Heating, Air Conditioning, and Refrigeration Mechanics and InstallersGuide
Mobile Heavy Equipment Mechanics, Except EnginesProfile
Motorboat MechanicsProfile
Motorcycle MechanicsProfile
Outdoor Power Equipment and Other Small Engine MechanicsProfile
Stationary Engineers and Boiler OperatorsProfile

Other Sources

  • California Air Resources Board
  • California Energy Commission
  • Alternative Fuels and Advanced Vehicles Data Center
  • United States Environmental Protection Agency
  • Amalgamated Transit Union
  • Association of Diesel Specialists
  • International Association of Machinists and Aerospace Workers
  • International Brotherhood of Teamsters
  • International Union of Operating Engineers
  • International Union, United Automobile, Aerospace and Agricultural Implement Workers of America
  • • National Alternative Fuels Training Consortium
  • United Automobile, Aerospace and Agricultural Implement Workers of America International Union

These links are provided for your convenience and do not constitute an endorsement by EDD.

For the Career Professional

The following codes are provided to assist counselors, job placement workers, or other career professionals.

SOC - Standard Occupational Classification49-3031
O*NET - Occupational Information Network
   Bus and Truck Mechanics and Diesel Engine Specialists49-3031.00
   Interest Codes (RIASEC)RCI
CIP - Classification of Instructional Programs
   Diesel Mechanics Technology/Technician 470605
TOP - Taxonomy of Programs (California Community Colleges)
   Diesel Technology094700