Heavy-Duty Truck Services
Mobile heavy-duty semi-truck and trailer roadside services
Find the repair your truck needs. Every service below is performed on-site by Smiths Truck Service across North Carolina and Virginia — call 336-320-8509 for 24/7 roadside repair.
Find your repair
Twenty roadside repairs for semi trucks and trailers, grouped by system. Locate your issue below, then open its service page for symptoms, likely causes, and what can be completed roadside.
Emergency roadside & dispatch
When a truck stops on the road, this is where to start. Call for 24/7 mobile heavy-duty repair and we discuss your location, the fault, and what work may be possible on site.
24/7 Emergency Semi Truck Roadside Repair
Mobile heavy-duty repair dispatched day or night across North Carolina and Virginia.
Mobile Heavy-Duty Diesel Diagnostics
On-site diagnostic work on commercial diesel trucks and trailers.
Emissions & engine diagnostics
Warning lights, derate faults, and failed regens. We read the codes, trace the cause, and explain which repairs can be completed roadside.
Check Engine & Stop Engine Diagnostics
Fault code retrieval and diagnosis of check engine and stop engine warnings.
DEF System Diagnostics & Repair
Diesel exhaust fluid system faults, doser faults, and related repairs.
DPF, DOC & SCR Emissions Diagnostics
Filter and catalyst diagnostics across the aftertreatment system.
NOx Sensors & DEF Doser Diagnostics
Sensor readings and doser function checked against the fault at hand.
Forced Regens & Derate Diagnostics
Regen attempts and derate condition diagnosis on site.
Engine, cooling & air systems
Leaks, overheating, and air pressure faults. We trace the source and repair what can be repaired at the roadside.
Coolant Leaks & Radiator Repair
Coolant loss traced and radiator repairs attempted on site.
Water Pumps, Thermostats & Hoses
Cooling system components diagnosed and replaced where feasible.
Air Leaks, Air Lines & Air Manifolds
Air system leaks located and lines or manifolds repaired.
Turbo Boost Leaks, Boots & Intercoolers
Boost pressure faults traced to boots, pipes, and intercoolers.
Brakes, drivetrain & electrical
Brake faults, driveline issues, and electrical failures on the truck and trailer — diagnosed and repaired where the roadside allows.
Brake Chambers, Shoes & Drums
Brake components inspected and repaired on site.
Semi Truck & Trailer Brake Repair
Air and hydraulic brake faults on truck and trailer.
Trailer Air Valves & Electrical Repair
Trailer valve and wiring faults diagnosed and repaired.
Wheel Seals, Hub Caps & Bearings
Hub and bearing faults found and addressed roadside.
Batteries, Alternators & Starters
Charging and starting faults diagnosed and repaired.
Electrical Wiring, Lights & Sensors
Wiring, lighting, and sensor faults traced and fixed.
Transmissions, Clutches & Actuators
Drivetrain faults diagnosed, with limits explained plainly.
Differentials & Driveline Diagnostics
Differential and driveline faults traced on site.
Semi Truck & Trailer Tire Replacement (New/Used Only, No Patching)
Tire replacement with new or used tires — no patching.
Call 336-320-8509 for 24/7 roadside repair
Stranded on I-77, I-40, or US-52? Smiths Truck Service provides 24/7 mobile heavy-duty semi-truck and trailer roadside repair across North Carolina and Virginia, based in Mount Airy, NC. Whether roadside completion is possible depends on the fault and the conditions where your truck sits.