Heavy-Duty Diesel Systems Technician
Zum
St. Louis, MO, USA
Posted on Mar 30, 2026
What a Day Looks Like
You start your shift by reviewing driver notes and opening work orders. A quick test drive during a Preventative Maintenance check helps you confirm reported concerns. Back in the bay, you dive into diagnostics, tracing issues across steering, electrical, cooling, lubrication, braking, drivetrains, suspensions, power steering units, clutches, transmissions, and oil/temperature/fuel control components—always working within your qualification level and in line with all federal, state/provincial, and local standards.
Midday, you might team up with a Tech I to assist with a rebuild—engines, transmissions, or differentials—coaching where appropriate and keeping the job moving. For any major repair, you ensure the proper inspections and approvals are secured before a vehicle leaves the maintenance facility. Throughout the day you identify and escalate additional repair needs, including those requiring a higher-qualified technician, so nothing gets missed.
When the call comes, you’re ready for a road response—performing on-the-road diagnostics and fixes to minimize downtime. You capture accurate records of time, parts, and work performed on the required forms. Before clocking out, you brief the Lead Technician on any unsafe maintenance conditions or signs of vehicle abuse you observed. Then it’s tools away and floors swept—keeping a safe, clean, efficient workspace that meets company housekeeping and safety rules, as well as applicable regulations. AM/PM coverage and overtime may be part of your week.
Core Responsibilities
You start your shift by reviewing driver notes and opening work orders. A quick test drive during a Preventative Maintenance check helps you confirm reported concerns. Back in the bay, you dive into diagnostics, tracing issues across steering, electrical, cooling, lubrication, braking, drivetrains, suspensions, power steering units, clutches, transmissions, and oil/temperature/fuel control components—always working within your qualification level and in line with all federal, state/provincial, and local standards.
Midday, you might team up with a Tech I to assist with a rebuild—engines, transmissions, or differentials—coaching where appropriate and keeping the job moving. For any major repair, you ensure the proper inspections and approvals are secured before a vehicle leaves the maintenance facility. Throughout the day you identify and escalate additional repair needs, including those requiring a higher-qualified technician, so nothing gets missed.
When the call comes, you’re ready for a road response—performing on-the-road diagnostics and fixes to minimize downtime. You capture accurate records of time, parts, and work performed on the required forms. Before clocking out, you brief the Lead Technician on any unsafe maintenance conditions or signs of vehicle abuse you observed. Then it’s tools away and floors swept—keeping a safe, clean, efficient workspace that meets company housekeeping and safety rules, as well as applicable regulations. AM/PM coverage and overtime may be part of your week.
Core Responsibilities
- Diagnose and repair medium/heavy vehicles across steering, electrical, cooling, lubrication, braking, drivetrain, suspension, power steering, clutch, transmission, and oil/temperature/fuel regulation systems.
- Assist Tech I personnel with engine, transmission, and differential rebuilds as assigned by the manager.
- Conduct test drives during Preventative Maintenance to validate driver-reported concerns and after service to confirm successful repairs.
- Coordinate required inspections and obtain approval for all major repairs prior to vehicle release.
- Identify and report any additional maintenance or repairs needed, including those requiring higher-qualified technicians.
- Complete tasks assigned by the manager or lead under supervision.
- Document labor time, parts used, and all services performed on the designated forms.
- Perform road calls and on-the-road repairs as needed.
- Maintain a safe, orderly, and compliant work area; report unsafe practices and vehicle abuse to the Lead Technician.
- Work assigned shifts (AM/PM) and overtime as needed.
- 2–4 years of medium/heavy truck fleet repair experience.
- Strong diagnostic capability with electrical and A/C expertise.
- Solid technical knowledge of major vehicle systems and diesel equipment.
- Fleet background with both diesel and gasoline systems.
- Ownership of recommended minimum hand tools for Medium/Heavy Duty Diesel work.
- Sound judgment and decision-making skills.
- Valid CDL or ability to obtain within 90 days of hire.
- ASE certification in brakes, suspension, engine, electrical, and A/C—or Master School Bus/Master Truck Technician.