Heavy Equipment Mechanics perform maintenance, inspection, diagnostics, fabrication, calibration, and repair activities on various pieces of heavy (greater than 26,000 GVWR) and construction (on- and off-road) vehicles and equipment, including but not limited to heavy-duty truck and semi-tractors, tractor/trailer combinations, water trucks, drill rigs, material spreaders, 6-wheel drive vehicles, excavators, dozers, high pressure pumps, graders, asphalt paving equipment, cranes, snowcats and groomers, underbody blades, single- and tandem-axle dump trucks, dump bodies, snow plows, fire apparatus, crawler tractors and trailers, front-end loaders, backhoes, trailers, electronic message boards and signs, street sweepers, forklifts, aerial towers, man lifts, bucket trucks, and facility emergency power generation equipment.

Diagnoses, services, and repairs various complex systems and permanently-mounted apparatus or implements that are found on heavy-duty vehicles and equipment such as mechanical and computer electronic controls, air brake systems, hydraulic systems such as constant flow and variable flow hydraulics, computer controlled automatic and manual transmissions, high/low voltage and permanently-mounted (not hand-portable) generators used for emergency power and emergency operations, diesel and gas engines, propane powered equipment, and pneumatic systems.

Heavy Equipment Mechanics maintain and repair heavy-duty vehicles and equipment (greater than 26,000 GVWR). Light- or medium-duty vehicle or marine vessel work may only be performed in this series a minority of the time and as part of a heavy equipment fleet. Automobiles and other light-duty vehicle (under 15,000 GVWR) repairs are defined in the Automotive Mechanic class series. Medium-duty vehicles (26,000 GVWR or less without air brakes) and commercial/industrial equipment are found in the Equipment Technician series.
Positions troubleshoot malfunctions in heavy vehicles and equipment and make repairs.

Parts purchasing, analysis, and inventory are defined in the Equipment Technician series and may be performed here only in addition to heavy equipment mechanic work.

Performs routine, sub-journey maintenance, repair, and service activities on heavy-duty vehicles, and equipment, and assists a higher-level mechanic in the completion of preventive maintenance, repair, and outfitting or modification of equipment. This may include mechanic work on marine vessels, marine vessel engines, and components as part of a larger fleet of heavy vehicles and equipment.

This is the entry level of the series and the work at this level is planned and facilitates the training needs of an entry-level technician. Work is primarily routine within established protocols and under the direction of a higher-level mechanic.

Assists higher-level mechanics in the diagnosis, service, and repair of various systems found on heavy equipment such as mechanical and computer electronic controls, air brake systems, transmissions, computer controlled automatic and manual transmissions, high voltage generators, propane powered equipment, and pneumatic systems;

Performs routine scheduled maintenance checks and adjustments on fluid levels, hoses, belts, brakes, tires, and clutches; changes filters and oil, and lubricates vehicles and motor driven equipment.

Tunes gas and diesel engines, services valves, fuel injection systems, fuel pumps, high pressure pumps and carburetors, fuel filters and turbo chargers, and pressure checks fuel filters, adjust injector heights, fuel racks, governors, etc.

Assists with repairing, rebuilding, replacing, or restoring remote and direct controlled electronic, pneumatic, hydraulic control systems for stationary and mobile equipment;

Performs routine inspection and replacement of pneumatic and hydraulic brake systems, brake shoes, pads, drums, hoses, calipers, cylinders, and any heavy-duty air brake systems.

Flushes radiator, replaces hoses and thermostat, repairs, or replaces radiator, water pump, fan drives, treatment filters, air intercoolers, and oil coolers.

Assists with repairing and replacing various power train and propulsion systems, drive shaft, differential, axle, manual, automatic and sophisticated computer-controlled transmissions, clutches, transfer cases, power take-off systems, transmission reversers, all-wheel drive steering axles, and final drives.

Assists with repairing, rebuilding, replacing, or restoring electrical systems (high and low voltage), batteries, lights, instruments, warning devices, controls and switches, computer controls, modules, alternators, starters, and defective cables, and wiring; includes 12 and 24-volt systems.

Replaces mufflers, manifolds, catalytic converters, Diesel Particulate Filter (DPF), Exhaust Gas Recirculation (EGR), and Silicon Controlled Rectifier (SCR) diesel emission systems, turbochargers, blowers, and pipes as part of exhaust and emissions control.

Repairs or replaces heater cores, condensers, compressors, hoses, and controls; recharges air conditioning systems.

Assists with repairing or replacing hydraulic pumps, hoses, valves, winches, and cylinders.

Assists with repairing or replacing air compressors, air dryers, brake valves, air tanks, and hoses.

Aligns and balances wheels; repairs or replaces medium/heavy suspension and steering systems, tie rods, ball joints, gear boxes, shock absorbers, springs, steering linkage, kingpins, power steering, hoses, pumps, walking beam suspensions, and air suspensions.

Adjusts, repairs, inspects, and replaces fifth wheel hitches, pintle hitches, and other coupling devices.

Assists with engine overhauls, replacing engines, and rebuilding engine components.

Assists other mechanics in repairing, rebuilding, replacing, or restoring chassis and component parts.

Assists with repairs and services on track drive sprockets, rails, idler wheels, hard bars, track adjusters, hydraulic reversers, final drives, brake bands, steering clutches, and hydrostatic transmissions;

Maintains service logs and records of maintenance on vehicles and motorized equipment using fleet maintenance and management software.

Determines need for repairs or adjustments, and either performs repairs or refers work to a higher-level mechanic.

Utilizes various shop tools and machinery including hand tools, pneumatic and power tools, mills, lathes, welders, torch sets, plasma cutter, and metal cutting saws, etc.;

Test drive or operate equipment to verify proper operation.

Prepares work orders and cost materials estimates.

Knowledge of: standard practices, materials, tools, and equipment used in the repair and maintenance of motor vehicles and engines; safety issues in the use of tools, equipment, and supplies used in repair of motorized vehicles and equipment; body and frame construction.

Ability to: With assistance, diagnose mechanical, electrical and hydraulic malfunctions; read manuals and schematics; rebuild engines and major driveline components; communicate with other mechanics about repair work needed; enter repair information in fleet maintenance management software.

There may be instances where individual positions must have additional licenses or certification. It is the employer’s responsibility to ensure the appropriate licenses/certifications are obtained for each position.

Persons legally authorized to work in the U.S. under federal law, including Deferred Action for Childhood Arrivals recipients, are eligible for employment unless prohibited by other state or federal law.

Two years of experience assisting skilled trades people in the repair and maintenance of heavy equipment. Successful completion of vocational technical training in heavy equipment may substitute year for year for experience. Equivalent training and/or education may substitute for experience.

Some positions may require a Commercial Driver’s License.

Equivalent education/experience.

Establish new job classification; range 56G; adopted June 23, 2025, effective July 1, 2025.