Construction Equipment Repairer

Army 91L Construction Equipment Repairers keep the Army's heavy iron running. Every dozer pushing a berm, every grader cutting a road, every loader staging materials at a forward base — a 91L is what stands between that machine working and that machine sitting deadlined. These mechanics troubleshoot, repair, and maintain the Army's construction equipment fleet: dozers, graders, scrapers, wheel loaders, backhoes, excavators, cranes, dump trucks, and asphalt distributors. Diesel engines, hydraulic systems, electrical subsystems, pneumatic controls, undercarriages, and HVAC on cabs all live under the 91L scope of work.

After 10 weeks of Basic Combat Training, 91Ls go through roughly 14 weeks of AIT at the U.S. Army Engineer School at Fort Leonard Wood, Missouri, taught by Company D, 554th Engineer Battalion in Training Area 244. The course covers nine major equipment platforms and walks through engine theory, hydraulic and pneumatic system troubleshooting, electrical fault isolation, and cab and HVAC repair. Marines from MOS 1341 (Engineer Equipment Mechanic) train alongside 91Ls in a combined Engineer School pipeline. In the fleet, 91Ls support engineer battalions, USACE construction projects, horizontal and vertical construction units, sapper companies, and combat heavy units. They live in ULLS-G and GCSS-Army for parts and work orders, manage Class IX (repair parts) demand, and answer to Operational Readiness (OR) rates the same way wheeled-vehicle mechanics answer to FMC.

What makes a 91L different from a civilian heavy-equipment tech: multi-OEM exposure on day one. A typical motor pool will have CAT, John Deere, Komatsu, and legacy Volvo iron sitting next to each other, and a 91L is expected to work across all of it. Add diesel diagnostics, hydraulics, and electrical troubleshooting in the same skill set and you have a candidate that dealer service departments, pipeline contractors, and infrastructure firms compete for. For the same-branch comparisons, see 91B Wheeled Vehicle Mechanic and 91D Power Generation Equipment Repairer, or browse all military-to-civilian career paths. For trade-route options outside the federal track, our military-to-trade careers guide covers the apprenticeship side of this transition.

I worked federal environmental and engineering positions after the Navy, and 91L is one of the cleanest fits for the WG/GS facilities and engineering side I have seen. Heavy equipment maintenance, hydraulics, and diesel diagnostics map directly to WG-5803 Heavy Mobile Equipment Mechanic and the GS-1601 facility-ops track at USACE, NPS, and BLM. On the private side, mining, pipeline, and infrastructure contractors hire this background fast because multi-OEM dealer techs are rare. — Brad Tachi, Navy Diver veteran & BMR founder

Civilian heavy-equipment dealers and infrastructure contractors actively recruit 91Ls because the multi-OEM, hydraulic-plus-diesel-plus-electrical skill set is genuinely rare. According to the Bureau of Labor Statistics OEWS May 2024 data, Mobile Heavy Equipment Mechanics (49-3042) earn a national median of around $64,150, Bus and Truck Mechanics (49-3031) earn around $60,640, Industrial Machinery Mechanics (49-9041) earn around $63,510, and First-Line Supervisors of Mechanics, Installers, and Repairers (49-1011) earn around $79,250.

The dealer-tech path is where 91Ls compete most directly. Caterpillar, John Deere, Komatsu, Volvo CE, and Case New Holland all run factory-trained tier programs (CAT Technician Career Development, John Deere TECH, Komatsu KTAP) where pay scales rise with each tier the technician completes. Top-tier dealer techs at CAT and Deere regularly clear $80,000-$100,000+ in higher cost-of-living markets, and field service engineers (FSEs) traveling to job sites often clear that bar earlier in their career. Field service work is where 91L deployment-style maintenance experience pays off — diagnosing in the dirt, on a generator, in the rain, with a customer waiting on the machine.

Pipeline and infrastructure construction is the second strong lane. Companies like Kiewit, Bechtel, Fluor, MasTec, and large mining operators (Freeport-McMoRan, Newmont, Barrick) hire heavy mechanics into roles that pay well above national medians because of overtime, per diem, and remote-site premiums. The trucking and leasing world (Penske, Ryder, U-Haul fleet maintenance, Holt Cat dealerships, Foley Equipment) offers more stable home time with strong pay. Cross-branch parallels include Navy CM Construction Mechanic, Navy EO Equipment Operator, Marines 1142 Engineer Equipment Mechanic, and Air Force 2T3X1 Vehicle Maintenance — all of those communities feed into the same civilian dealer and contractor talent pool.

For 91Ls considering the trades route instead of straight dealer work, the union heavy-equipment world (IUOE Local apprenticeships, signatory contractors) is a strong entry — see our Helmets to Hardhats apprenticeships guide and military-to-construction-management transition for context.

The federal heavy-equipment maintenance lane is one of the cleanest WG/GS pathways available to any military mechanic, and 91L is right in the middle of it. The federal government runs heavy equipment shops at the U.S. Army Corps of Engineers (USACE), National Park Service (NPS), Bureau of Land Management (BLM), Department of Veterans Affairs cemeteries, GSA Fleet Management, USPS vehicle maintenance facilities, and Air Force Civil Engineer (CE) squadrons that hire civilians. Veterans'' Preference applies to all of these positions and gives former 91Ls a measurable advantage at the cert list stage.

The most direct landing is WG-5803 Heavy Mobile Equipment Mechanic, where 91L AIT plus motor pool experience qualifies veterans into the WG-8 through WG-10 range immediately. WG-5806 Mobile Equipment Servicing covers the lower-tier servicing work (lubrication, tire and battery service, light maintenance) and is a fast-entry path for early-career 91Ls. WG-5378 Powered Support Systems Mechanic covers ground support equipment (GSE) — generators, hydraulic test stands, environmental control units — which lines up well for 91Ls who cross-trained or assisted 91D power-generation work. WG-5306 Air Conditioning Equipment Mechanic is a related WG track for those who specialized in HVAC work on equipment cabs and shop systems.

For 91Ls with NCO supervisory experience, the GS side opens up. GS-1670 Equipment Specialist is the technical equipment-management series (writing specs, evaluating equipment, supporting acquisition) and is where senior 91Bs and 91Ls with project work tend to land. GS-1601 General Facilities and Equipment covers facility and equipment operations management — running the shop, not turning the wrenches — and is a strong fit for shop foremen and motor-sergeant types. GS-0802 Engineering Technician opens engineering support roles at USACE, NAVFAC, and Air Force CE squadrons, particularly for 91Ls who supported construction projects with mechanic-on-site duties.

For more on writing the federal-style resume these tracks require, see our NCOER to resume bullets guide and our dedicated federal resume builder. When you''re ready, you can build your resume free at BMR.

If you''re staying in heavy equipment, construction, or industrial maintenance, your terminology translates directly. Dealers, pipeline contractors, and infrastructure firms know what PMCS and Class IX mean in concept, even if they call it a PM inspection and an MRO part. This section is for 91Ls targeting careers outside heavy equipment — project management, operations, manufacturing, safety, or energy roles where the hiring manager has never opened ULLS-G in their life.

These translations reframe your shop experience into business language that resonates with non-technical hiring managers. They are not just word swaps — they show how to quantify and contextualize your motor pool experience for a completely different audience. For the broader military-to-civilian glossary, see our 50 military terms civilian equivalents glossary, and when you''re ready to put it on paper, build your resume at BMR.