Diesel Mechanic job description: duties, skills and qualifications.

Core duties

16

O*NET task statements

Preparation

Job Zone 3 of 5

medium preparation

Typical entry education

High school diploma or equivalent

BLS 2025–35

Median pay

$61,770

BLS May 2025

Data Government data groups this job as Bus and Truck Mechanics and Diesel Engine Specialists (O*NET-SOC 49-3031.00). Figures on this page are for that occupation.

1. Use handtools, such as screwdrivers, pliers, wrenches, pressure gauges, or precision instruments, as well as power tools, such as pneumatic wrenches, lathes, welding equipment, or jacks and hoists. importance 4.5 of 5
2. Inspect brake systems, steering mechanisms, wheel bearings, and other important parts to ensure that they are in proper operating condition. importance 4.3 of 5
3. Raise trucks, buses, and heavy parts or equipment using hydraulic jacks or hoists. importance 4.2 of 5
4. Adjust and reline brakes, align wheels, tighten bolts and screws, and reassemble equipment. importance 4.2 of 5
5. Attach test instruments to equipment, and read dials and gauges to diagnose malfunctions. importance 4.2 of 5
6. Perform routine maintenance such as changing oil, checking batteries, and lubricating equipment and machinery. importance 4.2 of 5
7. Examine and adjust protective guards, loose bolts, and specified safety devices. importance 4.1 of 5
8. Inspect, test, and listen to defective equipment to diagnose malfunctions, using test instruments such as handheld computers, motor analyzers, chassis charts, or pressure gauges. importance 4.1 of 5
9. Rewire ignition systems, lights, and instrument panels. importance 4.0 of 5
10. Test drive trucks and buses to diagnose malfunctions or to ensure that they are working properly. importance 4.0 of 5
11. Diagnose and repair vehicle heating and cooling systems. importance 4.0 of 5
12. Inspect, repair, and maintain automotive and mechanical equipment and machinery, such as pumps and compressors. importance 4.0 of 5
13. Inspect and verify dimensions and clearances of parts to ensure conformance to factory specifications. importance 4.0 of 5
14. Disassemble and overhaul internal combustion engines, pumps, generators, transmissions, clutches, and differential units. importance 3.9 of 5
15. Adjust or repair computer controlled exhaust emissions devices. importance 3.9 of 5
16. Rebuild gas or diesel engines. importance 3.9 of 5

Work activities O*NET rates most important here: Repairing and Maintaining Mechanical Equipment, Inspecting Equipment, Structures, or Materials, Getting Information, Identifying Objects, Actions, and Events and Operating Vehicles, Mechanized Devices, or Equipment.

Also part of the job

Supplemental tasks O*NET lists for this occupation: less central than the core duties above, and not done in every job.

• Measure vehicle emissions to determine whether they are within acceptable limits.
• Follow green operational practices involving conservation of water or energy or reduction of solid waste.
• Operate valve-grinding machines to grind and reset valves.

Knowledge areas: Mechanical, Transportation, Education and Training, English Language and Public Safety and Security.

Software O*NET lists for this occupation: Autodesk AutoCAD, Dassault Systemes SolidWorks, Microsoft Excel, Microsoft Office software, Microsoft Word, SAP software. These are examples O*NET records for the job, not a list of tools every employer uses or a checklist of what you must know.

• Education: BLS lists a high school diploma or equivalent as the typical entry-level education.
• Experience: BLS lists no work experience in a related occupation as typical to enter.
• Training on the job: BLS lists long-term on-the-job training as typical once hired.
• Preparation: O*NET places the job in Job Zone 3 of 5 (medium preparation). Previous work-related skill, knowledge, or experience is required for these occupations.
• Licenses and certifications: not listed here. A license is a legal requirement set by a state; a certification is a credential from a private or professional body. Rules vary by state and employer, and a missing entry on this page does not mean none is required: check with your state's licensing board and see how to become a diesel mechanic.

The most common answer among diesel mechanics surveyed by O*NET is a post-secondary certificate (39%).

Job title: Diesel Mechanic
[Company] · [City, State] · [Full-time or part-time] · [Pay range, where your state requires one]

About the role
[Company] is hiring a Diesel Mechanic to diagnose, adjust, repair, or overhaul buses and trucks, or maintain and repair any type of diesel engines.
[One sentence on your team and why this role matters.]

What you will do
- Use handtools, such as screwdrivers, pliers, wrenches, pressure gauges, or precision instruments, as well as power tools, such as pneumatic wrenches, lathes, welding equipment, or jacks and hoists.
- Inspect brake systems, steering mechanisms, wheel bearings, and other important parts to ensure that they are in proper operating condition.
- Raise trucks, buses, and heavy parts or equipment using hydraulic jacks or hoists.
- Adjust and reline brakes, align wheels, tighten bolts and screws, and reassemble equipment.
- Attach test instruments to equipment, and read dials and gauges to diagnose malfunctions.
- Perform routine maintenance such as changing oil, checking batteries, and lubricating equipment and machinery.
- Examine and adjust protective guards, loose bolts, and specified safety devices.
- Inspect, test, and listen to defective equipment to diagnose malfunctions, using test instruments such as handheld computers, motor analyzers, chassis charts, or pressure gauges.

What we are looking for
- [Education: BLS lists a high school diploma or equivalent as typical for this occupation; set the level this role truly needs]
- [Experience: BLS lists no related work experience as typical to enter; set what this role needs]
- Strength in troubleshooting, repairing and operations monitoring
- Working knowledge of Mechanical and Transportation
- [Software your team uses, e.g. Autodesk AutoCAD or Dassault Systemes SolidWorks]
- [Any license or certification your state or company requires]

[Schedule, benefits and how to apply]

Illustrative: every name, employer, school, date and number in these samples is fictional or a bracketed placeholder. Replace each bracket with your own true details; never copy a result you did not achieve.

Not a real job posting. This template is TryHired's illustration built from government occupational data. It is not an opening at any employer, and no employer wrote it.

The median annual wage was $61,770 in May 2025. The median hourly wage was $29.70. BLS estimates about 289,960 jobs in this occupation in the U.S.

BLS projects employment of Bus and Truck Mechanics and Diesel Engine Specialists to grow 3.6% from 2025 to 2035, with about 24,400 openings a year over that period, including openings to replace workers who leave.

See the full diesel mechanic salary breakdown by percentile, state and metro.

• Read a real diesel mechanic posting next to the core duties above. Duties it repeats, such as “Use handtools, such as screwdrivers, pliers, wrenches, pressure…”, tell you what that employer weighs most; anything it adds is specific to that team.
• Tailor your resume to the posting, not to this page: describe only diesel mechanic work you have actually done, with your own results.
• Prepare a story for each of the top-rated skills (troubleshooting and repairing); diesel mechanic interview questions turns them into practice questions.