Diesel Mechanic in Illinois: Salary, License Requirements, and How to Start
Repair and maintenance
Illinois employs 11,320 diesel mechanics, with a statewide median of $64,340 and wide variation by city and experience. Here is the real wage data, the exact Illinois licensing picture, and where to train.
What Diesel mechanics Earn in Illinois (May 2025)
- Illinois median pay
- $64,340 (May 2025)
- Starting range (10th percentile)
- $44,760
- Experienced (75th percentile)
- $80,640
- Top earners (90th percentile)
- $97,670
- Employed in Illinois
- 11,320
- U.S. median (for comparison)
- $60,660 (May 2024)
Wages vary substantially by metro. Median annual pay for diesel mechanics in major Illinois markets:
- Peoria
- $63,850 (250 employed)
- Springfield
- $62,000 (130 employed)
- Rockford
- $61,020 (310 employed)
What That Pay Is Worth in Illinois
Prices in Illinois run right about the national average (cost-of-living index 100.0 vs a U.S. baseline of 100, 2024), so the $64,340 median holds roughly its face value.
Job Outlook in Illinois (2024–2034)
Illinois is projected to grow diesel mechanics employment +2.8%, about in line with the +2.4% projected nationally. The state expects about 870 openings a year, counting both growth and workers who retire or move on.
Illinois License and Certification Requirements
ASE Medium/Heavy Truck Certification (national — no state license) — regulated by the No Illinois state license required for diesel mechanics.
- Illinois does not require a state license for diesel mechanics. The recognized credential is ASE (National Institute for Automotive Service Excellence) Medium/Heavy Truck certification (Series H: H1–H8 cover the main diesel systems; T-Series covers transit buses). Most employers consider ASE certification when making hiring and wage decisions.
- Entry paths: (1) Enroll in a diesel technology program at a community or technical college (12–24 months) to earn foundational theory and lab experience, then enter the industry. (2) Start as a lube tech or diesel apprentice helper at a dealership or fleet shop and work toward certifications on the job.
- Manufacturers (Caterpillar, Cummins, Detroit Diesel, Allison) offer factory training for their specific engines — a strong career differentiator. EPA 609 certification is required to work on A/C systems in heavy trucks.
Official requirements: No Illinois state license required for diesel mechanics →
Training in Illinois
Major diesel employers in Illinois include Kenworth, Peterbilt, and Freightliner dealerships; large trucking fleets (Werner, J.B. Hunt, Amazon Logistics); municipalities (bus fleets, heavy equipment); and construction/mining equipment dealers. ASE-certified technicians consistently earn $5–$10/hr more than non-certified peers.
Real training providers and registered apprenticeships in Illinois include:
- Aviation Institute of Maintenance-Chicago — Certificate
- Black Hawk College — Certificate / Associate
- Carl Sandburg College — Certificate / Associate
- City Colleges of Chicago-Harry S Truman College — Certificate / Associate
Is This the Right Move for You?
Best for: People who like large, powerful machinery and want solid wages without a 4-year degree.
Think twice if: Grease, diesel exhaust, heavy components, and shop environments sound miserable rather than satisfying.
Why it's resilient: Diesel engines power trucks, buses, heavy equipment, and generators — hands-on diagnosis and repair that cannot be done remotely.
First Steps
Look for diesel technology programs at community colleges and vocational schools, or apply directly as a shop helper.
Frequently Asked Questions
How much do diesel mechanics make in Illinois?
The median wage for diesel mechanics in Illinois is $64,340 per year (May 2025, BLS). Entry-level pay (10th percentile) starts around $44,760, and top earners (90th percentile) make about $97,670. Pay varies by metro and years of experience.
What license or certification do you need to become a Diesel Mechanic in Illinois?
ASE Medium/Heavy Truck Certification (national — no state license), overseen by the No Illinois state license required for diesel mechanics. Illinois does not require a state license for diesel mechanics. The recognized credential is ASE (National Institute for Automotive Service Excellence) Medium/Heavy Truck certification (Series H: H1–H8 cover the main diesel systems; T-Series covers transit buses). Most employers consider ASE certification when making hiring and wage decisions.
Is being a Diesel Mechanic a good career in Illinois?
Diesel engines power trucks, buses, heavy equipment, and generators — hands-on diagnosis and repair that cannot be done remotely.
Which Illinois metros pay diesel mechanics the most?
Among Illinois metro areas, Peoria leads at $63,850, followed by Springfield ($62,000), Rockford ($61,020). Local pay tracks regional demand and cost of living, so the highest-paying metro isn't always the best net move.
Where can I train to become a Diesel Mechanic in Illinois?
Real Illinois options include Aviation Institute of Maintenance-Chicago, Black Hawk College, Carl Sandburg College. Most diesel mechanics start with an accredited program, then earn the credential the state or employer requires.
Is Diesel Mechanic a growing career in Illinois?
Illinois projects diesel mechanics employment to change +2.8% from 2024 to 2034, with about 870 openings a year — a growing field in the state.
Sources and Verification
Wage data: U.S. Bureau of Labor Statistics, Occupational Employment and Wage Statistics (May 2025), Illinois statewide and metro estimates for SOC 49-3031. Licensing summary compiled from the No Illinois state license required for diesel mechanics (2026-06-11). Requirements change — always confirm current rules with the board and verify program costs and outcomes before enrolling.
BLS Occupational Outlook · O*NET Illinois wages · Illinois licensing/certification source
Employment projections: Projections Central / BLS Employment Projections (2024–2034); Cost of living: BEA Regional Price Parities.
Pay percentiles describe current workers, not entry-level offers; training costs and local demand vary, so verify locally before committing money or quitting a job.