Heavy-Duty fleet maintenance & mobile Truck Repair · Southern Ontario
Maximum Uptime. Minimum Downtime.
Mobile heavy-duty truck repair and fleet maintenance across Southern Ontario. We come to you — on the highway, at your yard, wherever you need us.
Call us anytime
519-300-5153
Services
What We Do
Full-service heavy-duty diesel repair and maintenance — trucks, equipment, pump houses, and more.
Mobile Truck Repair
We come to your location — highway, yard, or job site. No towing required.
Fleet Maintenance Programs
Scheduled PM services, mileage tracking, and inspection programs to keep your fleet running.
Emergency Roadside Assistance
Breakdowns don't wait. Fast response emergency truck repair across Southern Ontario.
Brake Repairs & Inspections
Full brake system service — drums, pads, chambers, slack adjusters, and CVIP inspections.
Diesel Engine Diagnostics
Detroit Diesel, Cummins, CAT, and PACCAR engines diagnosed and repaired on-site.
Aftertreatment Systems
DPF, DEF, SCR, and EGR diagnostics and repairs. Get your emissions systems back in compliance.
Pump Houses & Stationary Diesel
Service and repair for diesel-powered pump houses, generators, and stationary industrial engines.
Heavy Equipment & Off-Road
Diesel repair for excavators, loaders, graders, and other off-road construction equipment.
Electrical & Wiring Diagnostics
Full electrical diagnostics — chassis wiring, lighting, sensors, and ECM/ECU fault codes.
10+
Years Heavy-Duty Experience
Fast
Emergency Response
Southern ONtario
Wide Service Area
Multi-Brand
Freightliner, Cummins, Detroit
Why Choose Us
Why Fleets Choose JNM
We built JNM HD Commercial Repairs around one principle: your trucks need to be running. Every hour a truck sits is money out of your pocket. Our technicians are experienced heavy-duty specialists who understand fleet operations, tight schedules, and the pressure of keeping commercial vehicles on the road. We're honest about what needs to be done, fast when it matters, and thorough every time.
Fleet Maintenance Programs
Reduce Downtime with a Fleet Maintenance Program
Stop reacting to breakdowns and start preventing them. JNM HD Commercial Repairs works with trucking companies, delivery fleets, and commercial vehicle operators to build organized PM schedules — tracking service intervals, mileage, engine hours, and inspection requirements so nothing slips through the cracks.
Experienced heavy-duty technicians — diesel repair, Freightliner, Cummins, and more.
Need a Repair? We Come to You.
Mobile heavy-duty truck repair across Southern Ontario. Call now or request service online.