Diesel Service Technicians and Mechanics
1. OVERVIEW
Diesel service technicians and mechanics inspect, repair, and overhaul buses, trucks, and other vehicles powered by diesel engines. They diagnose problems, perform maintenance, and ensure engines meet emissions regulations. As technology advances, technicians also work with computer-based diagnostic systems and electronic components.
2024 Median Pay: $60,640/year ($29.15/hour)
Job Growth (2023–2033): +3% (as fast as average)
Typical Education: High school diploma or equivalent + long-term on-the-job training
2. ROLE BREAKDOWN BY LEVEL
ENTRY LEVEL
Job Titles: Diesel Mechanic Trainee, Shop Assistant, Maintenance Technician
Education: High school diploma or equivalent
Experience: None required
Certifications (Optional): Entry-level ASE certifications
Core Duties:
Assist with routine maintenance (oil changes, tire rotations)
Clean parts and shop equipment
Drive vehicles into/out of the shop
Follow instructions from senior mechanics Salary Range: $40,000–$52,000
MID LEVEL
Job Titles: Diesel Technician, Fleet Mechanic, Field Service Tech
Education: Certificate or associate degree in diesel repair (preferred)
Experience: 3–5 years of hands-on work
Certifications (Recommended): ASE certifications (drivetrain, electrical, PM inspection)
Core Duties:
Diagnose engine and system issues using electronic tools
Repair or replace diesel components
Interpret diagnostic codes and technical manuals
Perform emissions and safety inspections Salary Range: $52,000–$72,000
SENIOR LEVEL
Job Titles: Master Diesel Technician, Fleet Supervisor, Shop Foreman
Education: Associate degree + certifications
Experience: 6+ years with leadership or specialist experience
Certifications (Preferred): Master ASE Diesel Technician, CDL
Core Duties:
Oversee diagnostics, repairs, and technician workflows
Interface with vendors and parts suppliers
Manage training and quality assurance
Implement safety and EPA compliance protocols Salary Range: $72,000–$95,000+
3. HOW TO BECOME ONE
Minimum Education: High school diploma or GED
Postsecondary Options: Vocational/technical school or associate degree in diesel mechanics
Training: 3–4 years of on-the-job training (apprenticeship or technician trainee roles)
Licenses/Certifications:
ASE Diesel Certifications (Entry-Level to Master Level)
CDL for test-driving large trucks
Soft Skills: Attention to detail, troubleshooting, communication, physical strength, customer service
4. SKILLS & TOOLS Core Skills:
Diesel engine systems
Troubleshooting and diagnostics
Emission controls and electronic systems
Welding and fabrication (occasionally)
Reading service manuals and interpreting codes
Tools & Technology:
Diagnostic scanners, laptops, OBD-II tools
Pneumatic tools, torque wrenches, jacks
Lathes, grinders, welding gear
Safety equipment (gloves, eyewear)
5. WORK ENVIRONMENT
Locations: Truck repair shops, bus depots, rental/leasing companies, roadside service, municipal fleet garages
Schedules: Full-time, often overtime; evening/weekend shifts common
Conditions: Noisy, physically demanding, exposure to oil, fuel, and exhaust
Injury Risk: Moderate; lifting heavy parts, minor cuts, and burns
6. JOB OUTLOOK
Drivers of Demand: Freight transport, fleet aging, EPA compliance requirements
Annual Openings: ~25,600 per year through 2033
Trends: Shift toward electric trucks may impact diesel-specific roles; however, diesel techs remain critical in freight, construction, and transit industries
7. RELATED OCCUPATIONS
Role: Automotive Service Technicians | Salary: $49,670 | Education Level: Postsecondary nondegree award
Role: Heavy Vehicle and Mobile Equipment Techs | Salary: $62,740 | Education Level: High school diploma
Role: Aircraft Mechanics | Salary: $79,140 | Education Level: Postsecondary nondegree award
Role: Small Engine Mechanics | Salary: $48,240 | Education Level: High school diploma
8. RESOURCES FOR LEARNING & ADVANCEMENT Certifications & Training:
ASE Diesel Certifications (www.ase.com)
NATEF-accredited diesel tech schools
Manufacturer training (e.g., Cummins, Freightliner)
Courses & Programs:
Universal Technical Institute Diesel Program
Lincoln Tech Diesel Technology Program
Community college diesel repair programs
Books:
"Modern Diesel Technology: Diesel Engines" by Sean Bennett
"Diesel Technology" by Andrew Norman and Robert Scharff
ASE Test Prep Manuals
Videos & Channels:
Diesel Creek (YouTube)
TheDieselDr (YouTube)
South Main Auto Repair
Communities:
iATN (International Automotive Technicians Network)
Reddit: r/DieselTechs
Diesel Tech Nation (Facebook)
9. REGIONAL DATA & EMPLOYMENT TRENDS
BLS Profile: Diesel Service Technicians
CareerOneStop: Salary and certification lookup by ZIP code
Projections Central: State-by-state diesel tech job growth
For full resources, certification guides, and a downloadable checklist to prepare for this career, visit: CareerOneStop Diesel Resources
