Job Specification | Heavy Duty Mechanic / Heavy Equipment Technician

🎯 Role Definition

The Heavy Duty Mechanic is the backbone of any operation that relies on heavy machinery, from construction and mining to transportation and logistics. This role is not just about fixing what's broken; it's about being a proactive, diagnostic expert who ensures the safety, reliability, and longevity of a company's most critical assets. A successful Heavy Duty Mechanic combines deep technical knowledge of diesel engines, complex hydraulic systems, and advanced electronics with a sharp, problem-solving mindset. You are the trusted technician who keeps the fleet moving, minimizes downtime, and ensures every piece of equipment operates at peak performance and in compliance with all safety standards.

📈 Career Progression

Typical Career Path

Entry Point From:

Heavy Duty Mechanic Apprentice
Automotive Mechanic (with upskilling in diesel)
Diesel Technician Trainee

Advancement To:

Lead Hand / Shop Foreman
Maintenance Supervisor / Fleet Supervisor
Fleet Manager or Maintenance Manager

Lateral Moves:

Field Service Technician
Technical Trainer or Instructor
Heavy Duty Parts Manager

Core Responsibilities

Primary Functions

Perform comprehensive diagnostic tests on heavy-duty trucks and equipment to accurately identify the root cause of mechanical, electrical, and hydraulic issues using both specialized software and manual troubleshooting techniques.
Conduct complete overhauls and rebuilds of major components, including diesel engines (e.g., Cummins, Paccar, CAT, Detroit), transmissions (manual and automatic), and differentials.
Execute preventative maintenance (PM) programs by performing scheduled servicing, fluid and filter changes, and thorough inspections to proactively identify and address potential failures.
Diagnose and repair complex after-treatment systems, including Diesel Particulate Filters (DPF), Selective Catalytic Reduction (SCR), and Exhaust Gas Recirculation (EGR) systems to ensure emissions compliance.
Service and repair advanced hydraulic systems, including pumps, valves, cylinders, and hoses on equipment such as excavators, loaders, and dump trucks.
Troubleshoot and repair sophisticated electrical and electronic systems, including starting and charging systems, lighting, onboard computers (ECMs), and multi-plex wiring, often requiring interpretation of complex wiring schematics.
Perform complete brake services on air and hydraulic brake systems, ensuring all components meet or exceed Department of Transportation (DOT) standards.
Conduct steering and suspension system repairs, including alignments, kingpins, and replacement of springs and shocks to ensure vehicle stability and safety.
Utilize welding and fabrication skills (MIG, Stick) to repair cracks in frames, buckets, or other structural components, and fabricate custom brackets or mounts as needed.
Complete detailed and accurate work orders, documenting all complaints, causes, and corrective actions taken, as well as logging all parts and labor time used for each job.
Perform official Commercial Vehicle Inspections (CVIP) or equivalent DOT annual inspections, meticulously checking all required components and completing the necessary legal documentation.
Respond to and repair equipment breakdowns in the field, demonstrating the ability to work independently and make critical decisions under pressure.
Mount, dismount, and balance heavy-duty tires, ensuring proper inflation and torque specifications are met.
Maintain a clean, organized, and safe work environment, adhering to all shop safety protocols, including Lockout/Tagout (LOTO) procedures.
Mentor and provide technical guidance to apprentice mechanics, sharing knowledge and helping to develop the next generation of technicians.
Liaise with the parts department to ensure the correct parts are sourced and ordered in a timely manner to minimize equipment downtime.
Test drive vehicles and operate heavy equipment before and after repairs to verify that the reported issues have been resolved and the equipment is functioning correctly.
Stay current with emerging vehicle technologies, new repair techniques, and industry best practices by participating in manufacturer-provided training and ongoing professional development.
Manage the proper handling and disposal of hazardous materials such as used oil, coolant, and solvents in accordance with environmental and safety regulations.
Calibrate and adjust machinery and equipment components to meet manufacturer specifications and ensure optimal performance.

Secondary Functions

Contribute to the continuous improvement of preventative maintenance schedules and standard repair procedures to enhance shop efficiency and equipment reliability.
Provide technical feedback to supervisors and management on recurring equipment issues to assist with root cause analysis and inform future purchasing decisions.
Collaborate effectively with equipment operators and drivers to gather detailed information about performance issues and ensure their concerns are fully addressed.
Participate in daily toolbox talks, safety meetings, and planning sessions to coordinate shop workflow and help prioritize the most critical repairs.

Required Skills & Competencies

Hard Skills (Technical)

Advanced Diesel Engine Diagnostics: Proficiency with OEM diagnostic software (e.g., Cummins INSITE, CAT ET, Detroit Diesel Diagnostic Link) to interpret fault codes and monitor live data.
Hydraulic System Expertise: Deep understanding of open and closed-loop hydraulic systems, with the ability to read schematics and troubleshoot complex flow and pressure issues.
Electrical & Electronic Systems Troubleshooting: Ability to read and interpret complex electrical schematics and use multimeters and other tools to diagnose issues in modern multiplexed systems.
After-Treatment System Repair: In-depth knowledge of DPF, SCR, and EGR systems, including forced regeneration procedures and component replacement.
Air Brake Systems: Comprehensive knowledge of truck and trailer air brake systems, including diagnostics and repairs (T-endorsement or equivalent certification is a strong asset).
Welding and Fabrication: Competency in SMAW (Stick) and GMAW (MIG) welding for structural repairs on heavy equipment and truck frames.
Powertrain and Driveline: Expertise in the removal, repair, and installation of transmissions, clutches, differentials, and drivelines.
HVAC Systems: Ability to diagnose and repair heating, ventilation, and air conditioning systems on heavy trucks and equipment.
-Technical Manual Interpretation: Skill in navigating and utilizing online service manuals, parts catalogs, and technical bulletins to find repair information.
Precision Measuring: Proficient use of precision measuring tools like micrometers, calipers, and bore gauges for internal engine and component work.

Soft Skills

Critical Thinking & Problem-Solving: A logical and methodical approach to diagnosing complex, multi-faceted equipment failures.
Attention to Detail: Meticulous and thorough in all inspections, repairs, and documentation to ensure safety and quality.
Time Management: Ability to prioritize a demanding workload, manage multiple jobs simultaneously, and meet deadlines in a fast-paced environment.
Strong Work Ethic: A reliable, self-motivated individual who takes pride in their work and can be counted on to complete tasks with minimal supervision.
Communication Skills: Clearly and concisely communicate technical issues and repair plans to supervisors, operators, and other team members.
Teamwork: Willingness to collaborate with, and assist, other technicians to solve problems and achieve team goals.
Adaptability: Openness to learning new technologies and repair methods as vehicles and equipment continue to evolve.

Education & Experience

Educational Background

Minimum Education:

High School Diploma or GED.
Diploma or Certificate from a recognized technical college in Heavy Duty Equipment Technology, Diesel Technology, or a related trade.

Preferred Education:

Journeyman Heavy Duty Equipment Technician (HDET) Red Seal Certification (in Canada) or ASE Master Medium-Heavy Truck Technician Certification (in the USA).

Relevant Fields of Study:

Heavy Equipment Technology
Diesel Mechanics
Commercial Transport Vehicle Mechanics

Experience Requirements

Typical Experience Range:

3-10+ years of progressive, hands-on experience as a journeyman-level mechanic working on a fleet of commercial transport trucks (e.g., Kenworth, Peterbilt, Freightliner) and/or heavy construction/mining equipment (e.g., Caterpillar, John Deere, Komatsu).

Preferred:

Experience in a dealership, fleet maintenance, or field service environment. Specialized experience with specific engine makes (Cummins, CAT), hydraulic systems, or advanced electronics is highly valued. A valid commercial driver's license (CDL/Class 1 or 3) is a strong asset.