Diesel Service Technicians and Mechanics

Diesel service technicians and mechanics (also known as diesel technicians) inspect, repair, or overhaul buses and trucks, or maintain and repair any type of diesel engine.

Duties

Diesel service technicians and mechanics typically do the following:

• Inspect and test brake systems, steering mechanisms, transmissions, engines, and other parts of vehicles
• Read and interpret diagnostic test results to identify mechanical problems
• Follow checklists to ensure that all critical parts are examined
• Repair or replace malfunctioning parts and other mechanical or electrical equipment
• Perform basic care and maintenance, including changing oil, checking fluid levels, and rotating tires
• Document repairs and maintenance performed, including parts used, hours worked, and vehicle condition
• Explain problems and repairs to clients 

Diesel technicians make engine repairs on a variety of vehicles, including trucks, bulldozers, commercial boats, and passenger vehicles. They also work on a vehicle’s electrical and exhaust systems to comply with pollution regulations.

In many shops, workers use computer diagnostic equipment to detect problems and adjust engine functions. Diesel technicians also use a variety of power and machine tools, such as pneumatic wrenches, lathes, grinding machines, and welding equipment. Hand tools are commonly used, including pliers, sockets and ratchets, and screwdrivers.

Technicians and mechanics who work primarily on automobiles are described in the profile on automotive service technicians and mechanics.

Technicians and mechanics who work primarily on farm equipment, construction vehicles, and railcars are described in the profile on heavy vehicle and mobile equipment service technicians.

Technicians and mechanics who work primarily on motorboats, motorcycles, and small all-terrain vehicles are described in the small engine mechanics profile.

Diesel service technicians and mechanics held about 319,900 jobs in 2024. The largest employers of diesel service technicians and mechanics were as follows:

Diesel technicians usually work in well-ventilated and sometimes noisy repair shops. They occasionally repair vehicles on roadsides or at worksites.

Injuries and Illnesses

Diesel service technicians and mechanics often lift heavy parts and tools, handle greasy or dirty equipment, and work in uncomfortable positions. Sprains and cuts are common among these workers. Diesel technicians need to follow some safety precautions when in the workplace.

Work Schedules

Most diesel technicians work full time, and some work more than 40 hours per week. Some repair shops extend their service hours during evenings and weekends. In addition, some truck and bus repair shops provide 24-hour maintenance and repair services.

Although diesel service technicians and mechanics typically learn on the job after a high school education, employers may prefer to hire candidates who have completed postsecondary training programs in diesel engine repair. In addition, industry certification may be required.

The median annual wage for diesel service technicians and mechanics was $60,640 in May 2024.

Employment of diesel service technicians and mechanics is projected to show little or no change from 2024 to 2034.

Despite limited employment growth, about 26,500 openings for diesel service technicians and mechanics are projected each year, on average, over the decade. Most of those openings are expected to result from the need to replace workers who transfer to different occupations or exit the labor force, such as to retire.