Diesel Fitter / Heavy Duty Mechanic
$140,000 – $200,000
About the role
Diesel Fitters and Heavy Duty Mechanics maintain and repair the mobile fleet on Australian mines — the haul trucks, excavators, loaders, dozers, graders and service trucks that move dirt and ore. On an iron ore mine like FMG's Cloudbreak or BHP's Yandi, that means 400-tonne Caterpillar 797 haul trucks, Liebherr 996 excavators and P&H rope shovels being serviced around the clock. A typical shift for a Field Service Fitter involves responding to breakdowns in the pit, diagnosing hydraulic and electronic faults, changing wheel motors and final drives, and getting equipment back into production as fast as safely possible. Workshop Fitters focus on scheduled component change-outs, engine and transmission rebuilds, and major statutory inspections. Experienced Fitters who specialise on high-value components — Cat 3512 engines, Komatsu 930E wheel motors, hydraulic pumps — routinely earn $180,000+ and can push toward $200,000 with shutdown work. The role is technically demanding: modern haul trucks are as much a rolling computer as a mechanical machine, and Fitters need to be comfortable with diagnostic laptops, CAN bus fault codes and manufacturer telemetry systems. Progression paths include Leading Hand, Reliability Engineer, Maintenance Planner and Supervisor. Because every major operator runs its own fleet, Fitters have strong mobility between BHP, Rio Tinto, FMG, Roy Hill, Glencore and the OEMs (Caterpillar / WesTrac, Komatsu, Liebherr). Rosters range from 8:6 residential in Perth-based workshops to 2:1 FIFO on remote sites.
Certificates & qualifications required
- Cert III Mobile Plant Technology (AUR31220) or Cert III Heavy Commercial Vehicle Mechanical Technology (AUR31120)
- Standard 11 Generic Mining Induction
- HR licence
- Working at Heights and Confined Space
- OEM-specific training (Caterpillar, Komatsu, Liebherr)
- First Aid
How to get a job in this field
- Complete a Heavy Diesel apprenticeship through TAFE or an OEM (WesTrac, Komatsu, Hastings Deering).
- Apply direct to mining operators or via labour hire — Programmed, WorkPac, One Key Resources.
- Specialise on a specific fleet type — Cat 793/797 or Komatsu 930E — to unlock the top of the band.
- Chase major component change-out and shutdown campaigns.
- Move toward Leading Hand or Reliability Engineer after 5–7 years.
