Heavy Duty Truck Repair For Class 6–8 Vehicles

About this service

Heavy duty repair is a different discipline from light vehicle work. Class 6, 7 and 8 trucks carry air brakes you can die for if you get them wrong, engines measured in litres rather than cubic inches, drivelines carrying torque that destroys anything undersized, and frames that flex and crack over a million miles of loaded running.

We work on those vehicles specifically. Our technicians are comfortable with the air systems, the aftertreatment, the hydraulics and the sheer weight of the equipment — and because we also run mobile service trucks, a great deal of heavy duty repair happens in your own yard rather than in a queue at a dealership.

What heavy duty truck repair involves

Diesel engine and aftertreatment

Hard starting, low power, excess smoke, coolant and oil loss, injector and fuel system faults, turbo problems, and the DPF, DEF and EGR faults that turn a working truck into a derated one. Diagnostics first, repair second.

Drivetrain

Clutch and release bearing complaints, input shaft and transmission faults, driveline vibration, worn universal joints and carrier bearings, differential noise and leaking pintle seals, and the wheel-end faults that follow a heavy load.

Air brake systems

Compressors, air dryers and desiccant cartridges, governors, foot valves, relay and quick-release valves, slack adjusters, chambers, hoses and tank reservoirs. Air brakes are not a system to improvise on, and we test what we repair.

Suspension and steering

Airliner and spring suspension, torque rods, track bars, radius rods, kingpins, drag links and tie-rod ends, steering gear boxes and leaking power steering, plus the alignment-related tyre wear that points to worn front-end components.

Chassis, frame and fifth wheel

Cracked frame rails and crossmembers, damaged gussets, worn fifth-wheel plates and locks, kingpin and coupling faults, and the structural welding that keeps a heavy-haul tractor in service.

Hydraulics and equipment

Wet kits, PTO-driven pumps, cylinders, valves, tanks and the high-pressure hose assemblies that fail under the worst possible load.

Common problems we are called for

If any of the following sounds familiar, call dispatch and describe it — it helps us send the right technician and the right parts on the first trip.

• Derate, low power or an engine warning on a loaded run
• Excessive black or white smoke and falling fuel economy
• Air pressure slow to build, or bleeding down when parked
• Brake pull, uneven wear or an air leak you can hear
• Vibration, clunking or noise through the driveline
• Steering wander, shimmy or heavy steering effort
• Truck sitting low or leaning on one side
• Cracks appearing in frame rails or crossmembers
• Hydraulic system slow, hot or refusing to lift a load
• A unit that will not pass a DOT roadside inspection

How Allday Fleet Solutions helps

Heavy duty faults are expensive to misdiagnose, so we invest the time in diagnostics rather than parts. Reading live data, watching pressures and temperatures, and testing under load tells us what is actually happening before anything is replaced.

Where the repair fits, we bring it to you. Engine accessories, air system components, brakes, suspension parts, hydraulics and welding are all realistic mobile jobs, and doing them in your yard removes the deadhead time from your cost.

Where the repair needs the shop — major engine work, transmission removal, differential rebuilds, frame straightening — we move the unit to the nearest of our Texas shops, keep the same technician on the ticket, and give you a realistic completion date instead of an open-ended one.

Where this applies

We handle heavy duty truck repair across the commercial vehicle types below and more. If your unit is not listed, call anyway — the list is not exhaustive.

• Class 8 semi tractors
• Heavy-haul and lowboy tractors
• Dump trucks and roll-off units
• Concrete and mixer trucks
• Crane and boom trucks
• Vacuum and hydro-excavator trucks
• Refuse and recycling trucks
• Heavy wreckers and rotators

What you get

• Diagnostics before parts, so you are not paying for guesses
• Mobile capability that keeps the repair in your own yard
• Air brake work done and tested to a standard, not a shortcut
• Structural and frame welding in house rather than outsourced
• Aftertreatment and derate faults repaired to clear the code properly
• Shop capacity for the jobs that genuinely need it