Five Steps in a Diesel Mechanic's Career Progression

Mechanics who work on tractor trailers and heavy trucks are responsible for the vehicles’ proper operation. They diagnose and repair mechanical issues, perform routine maintenance, test functionality and repair or replace parts, among other responsibilities.


If you’re interested in pursuing a career as a diesel mechanic, you can start out as a technician specialist with little or no prior experience. From there, it’s possible to move quickly up the ladder toward a mechanic role by taking advantage of training programs and apprenticeships. The typical career progression from tech specialist to mechanic to leadership position involves five steps:


  1. Start as a tech specialist with little or no experience required
  2. Progress to the apprenticeship program
  3. After completing an apprenticeship, become a trailer technician
  4. As a trailer technician, expand your training to become a diesel mechanic
  5. Mechanics can take on leadership roles and move to management positions


These steps are explained more fully below.

Is It "Mechanic" or "Technician"?

The terms mechanic and technician are often used interchangeably — you’ll see both used in job postings and other written materials. Once you’re hired, it’s really up to you whether you prefer to be called a mechanic or a technician. Someone with extensive experience and knowledge is often referred to as a senior technician.


5-Step Diesel Mechanic Career Progression

A career path for a diesel mechanic provides opportunities for growth and advancement. While you may already have repair and maintenance experience with small engines or autos, it’s not a requirement, making this an excellent career choice for on-the-job learning with plenty of room to grow.

1. Start as a Technician Specialist

This step needs to be completed before moving on to an apprenticeship program. You can expect to spend eight hours a day learning the skills that will help you take the next step. Four hours are spent on a loading dock learning how to move freight safely, and four hours are spent working with other trailer technicians.


Working in these settings as a tech specialist, you’ll be trained to ensure the trailer is prepared for loading, with everything inside working properly. You’ll gain experience with equipment such as the SafeStack system, trailer door mechanisms and basic electrical systems. You’ll also learn how to maintain accurate service records.

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2. Progress to the Apprentice Program 

After spending some time as a technician specialist, you may want to train in an apprentice program to become a trailer technician or a diesel mechanic. This can be a good choice if you don’t have much formal training, but you do have some mechanical aptitude, such as basic experience with:


  • Air brakes
  • Hydraulics
  • Electrical components
  • ABS brake systems
  • Basic mechanic’s tools


An apprentice program offers many benefits, including a clear path to advancement and pay raises when specific milestones are achieved. The ultimate goal of an apprentice is to acquire the skills needed to work on all equipment in the shop.


As an apprentice in a diesel mechanic program, you’ll start by working with experienced trailer technicians to learn everything about Class A vehicles, short of working on a running engine. The initial training includes working with electrical components, brakes, wheels and air valves in the brake chamber.


After mastering these initial skills, you’ll move on to working with engines on small equipment, such as forklifts. This stage of the apprentice program typically focuses on transmissions, brakes, hydraulics and control valves.


After you develop a deep understanding of service-level mechanics, forklifts and smaller engine work, you’ll graduate to working on big trucks. This is when you’ll learn everything you need to know about truck engines and becoming a Class A diesel mechanic.


You will:


  • Run diagnostics
  • Perform preventative and routine maintenance on heavy trucks and tractor trailers
  • Analyze major issues
  • Complete repairs
  • Make modifications
  • Conduct inspections

3. From Apprentice to Trailer Technician

After you graduate from the apprentice program, the next step is trailer technician. This is where you’ll apply your newly gained knowledge and skills by servicing Class A vehicles. It’s a position with a competitive salary that could start at $30/hour depending on your location. It can also provide further opportunities for advancement.


As a trailer technician, you can expect to:


  • Inspect, troubleshoot and repair the bodywork, systems and components of semi-trucks and trailers
  • Perform preventative maintenance on semi-trucks and trailers
  • Assemble and disassemble engines 
  • Clean fuel tanks
  • Replace, adjust and maintain hubs and axles
  • Inspect, service and replace trailer parts, such as tires
  • Perform brake, electrical and hydraulic systems checks and repairs 
  • Investigate performance issues in all systems and equipment
  • Ensure that trailers meet the regulations of the United States Department of Transportation (DOT) for road safety

4. Advance to a Diesel Mechanic Role

Some people really enjoy being a trailer technician and choose to remain in that position. However, if you’d like to continue training, you can grow into a role as a diesel mechanic.


While trailer technicians focus primarily on the trailer portion of a truck, mechanics use their specialized skills to become experts on tractor trailers and heavy trucks from end to end, including keeping the engine running. Other responsibilities include ensuring proper vehicle operation, performing routine truck maintenance, checking batteries, replacing oil and performing inspections on brake systems, wheel bearings and steering mechanisms to confirm they’re in good working order.


To repair trucks, mechanics use a variety of tools and equipment, including pressure gauges, pneumatic wrenches, welding equipment, screwdrivers, hoists and jacks, while following strict safety procedures. To diagnose defects in malfunctioning equipment, technology such as motor analyzers, handheld computers, chassis charts and other tools are often used.


As a diesel mechanic you can also expect to:


  • Test drive trucks to ensure they’re in good working order or to diagnose a problem
  • Repair cooling and heating systems, replacing parts, valves, bearings and gears as needed
  • Measure vehicle emissions to maintain them within acceptable levels
  • Inspect clearances and dimensions to ensure parts meet manufacturer standards

5. Move from Experienced Mechanic to Lead Technician or Shop Manager

A lead technician or shop manager oversees other mechanics and ensures that work is completed safely on time. This involves supervising teams, ordering mechanical parts and inspecting all work to ensure that required standards are met. Ultimately, the lead technician has responsibility for repairs, overhauls and maintenance being done properly, even though others perform the work.


In addition to managing mechanical workflow, lead technicians must also be capable of communicating effectively and be willing to provide assistance, training and advice. They also support the mechanics by performing road testing and assisting with recordkeeping, to ensure accurate equipment histories.

Get Started

If a career as a diesel mechanic suits you best, you need little to no experience to get started! The entry-level technician specialist position is ideal if you’re looking to expand your mechanical knowledge, learn new skills and start a career in this field.


If lead technician or shop manager is your goal, be assured you’ll learn everything you need as you progress through the steps from tech specialist to a leadership role. You’ll master your trade, while also having the opportunity to provide guidance to those following the same professional path.


If you are not sure where to start, contact XPO here and get some more information.