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Light vs. Heavy Diesel Mechanics


Diesel mechanics can specialize in light duty vehicles or heavy equipment. Like every decision in your career, both careers in heavy diesel and light diesel mechanics have their pros and cons to consider.

The Similarities

Even though the size and kinds of vehicles you work on are pretty different, you may be surprised at how similar the two specialties are. 

Light and heavy diesel mechanic positions both come with general responsibilities including repairing and servicing diesel vehicles. You'll troubleshoot problems and use computer software programs to run diagnostic procedures.

For both light and heavy diesel mechanics, certificates and/or degrees are becoming increasingly desired by employers. You could complete with a certificate program in as few as 10 months, whereas associate degree programs may take approximately 2 years.

The Differences

When choosing between becoming a light duty diesel mechanic or a heavy equipment mechanic, consider the type of vehicles and equipment you’ll work on, everyday responsibilities, and salary. Here’s how the two differ.

Light Duty Diesel Mechanic

Light duty diesel mechanics work on cars and trucks designed for on-the-road driving and shipping, including cars, light trucks, buses, and semi trucks.

Diesel service technicians and mechanics typically:

  • Consult with customers and read work orders to determine the work required
  • Plan work procedures, using technical charts and manuals
  • Inspect brake systems, steering mechanisms, transmissions, engines, and other parts of vehicles
  • Follow checklists to ensure that all critical parts are examined
  • Read and interpret diagnostic test results to accurately identify mechanical problems
  • Repair or replace malfunctioning components, parts, and other mechanical or electrical equipment
  • Perform basic care and maintenance, including changing oil, checking fluid levels, and rotating tires
  • Test-drive vehicles to ensure that they run smoothly

Heavy Duty Diesel Mechanic

Heavy equipment diesel mechanics specialize in vehicles and machines used for railroads, farms, mining, and construction, among others.

Heavy vehicle and mobile equipment service technicians typically do the following:

  • Consult equipment operating manuals, blueprints, and drawings
  • Perform scheduled maintenance, such as cleaning and lubricating parts
  • Diagnose and identify malfunctions, using computerized tools and equipment
  • Inspect, repair, and replace defective or worn parts, such as bearings, pistons, and gears
  • Overhaul and test major components, such as engines, hydraulics, and electrical systems
  • Disassemble and reassemble heavy equipment and components
  • Travel to worksites to repair large equipment, such as cranes
  • Maintain logs of equipment condition and work performed

In 2023, the average annual wage for diesel service technicians and mechanics was $59,920, according to bls.gov. The highest 10 percent of diesel mechanics made $82,430 or more.

Start with a well-rounded education from a school near you.

More reading: Fast certifications that pay well 

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