Heavy-Duty Truck Repair and Roadside Semi Service—We Come to You 24/7

When a truck goes down, freight stops moving—and that costs money. Cornwell’s Truck Repair delivers 24/7 roadside truck repair, mobile diagnostics, towing, and full-service heavy-duty shop repairs across the Arizona and New Mexico I-10 corridor.

Since 2008, drivers and fleets have trusted our ASE-certified diesel technicians to diagnose issues fast and perform both temporary roadside fixes and full mechanical repairs. If it can’t be fixed on-site, we tow directly to our shops in Tucson or San Simon  for full repairs.

Black tire with tread in focus, surrounded by stacks of tires in a tire shop.

Breakdowns rarely happen near a shop—which is why we come to you. Our roadside units are equipped for:

  • No-start diagnostics
  • Batteries, alternators and starters
  • Air brake leaks and chambers
  • Fuel delivery issues
  • Coolant and hose leaks
  • Electrical shorts
  • Sensor faults
  • Check-engine lights
  • Diesel/DPF/DEF issues
  • Forced regens
  • Tires

➡ Link to Mobile Service 24/7

➡ Link to Diesel/Semi Truck Repair

Mechanic using laptop to diagnose vehicle with hood open in a repair shop.

When breakdowns require more than roadside fixes, we perform complete shop service in Tucson and San Simon, including:

  • Engine diagnostics
  • Cooling system work
  • Turbo and fuel-system repairs
  • Electrical system repairs
  • Driveline repairs
  • Differentials
  • Clutches

➡ Link to Diesel/Semi Transmission Repair

Mechanic using a diagnostic tool on a car with its hood open in a garage.

Engines, Power Loss and Emissions Repairs

Modern diesel engines require advanced diagnostics. We repair:

  • DPF/DEF failures
  • EGR systems
  • Turbocharger issues
  • Hard starts
  • Power-loss complaints
  • Excessive smoke

➡ Link to Diesel/Semi Truck Repair

Mechanic working on car clutch with tool, wearing gloves. Silver and gray components.

Cornwell’s specializes in heavy-duty driveline systems:

  • Manual and automatic transmissions
  • Clutch replacement
  • Gearbox service
  • U-joints and yokes
  • Differentials

➡ Link to Diesel/Semi Transmission Repair

Underside view of a black off-road vehicle's suspension system with a large tire and coil-over shock absorber.

DOT and Safety-Critical Repairs

Stay compliant with fast DOT-related repair support:

  • Brakes
  • Lights
  • Steering
  • Suspension
  • Tires

➡ Link to Preventative and Fleet Maintenance

Blue semi-trucks parked in a lot at dusk; other trucks and vehicles in the background.

Every mile matters in freight. Cornwell’s offers scheduled fleet support:

  • Preventive PM programs
  • DOT prep
  • Recordkeeping
  • Oil and filter schedules
  • Tire rotation and inventory management

➡ Link to Preventative and Fleet Maintenance

Two Strategic Locations Serving I-10

We respond fast because we are positioned where truckers need help most:

𖡡 Tucson, AZ

𖡡 San Simon, AZ

We also support breakdowns in:

𖡡 Lordsburg, NM

𖡡 Eloy, AZ

𖡡 Nogales, AZ

𖡡 Yuma, AZ

𖡡 Oro Valley, AZ

𖡡 Avra Valley, AZ

𖡡 Marana, AZ

𖡡 Gila Bend, AZ

➡ Links to Tucson, San Simon, Lordsburg, Eloy, and Nogales

Why Truckers Choose Cornwell’s

Drivers depend on us because we deliver:

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24/7 mobile repair

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Heavy-duty towing

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ASE-certified mechanics

Garage with a car inside. Black and white icon.

Two full-service shops

Telephone icon with a clock, suggesting prompt call service.

Rapid response on I-10

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Honest pricing

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Trusted reputation since 2008

We fix trucks right—and get freight rolling again.

Reviews from Drivers We’ve Helped

Drivers constantly share feedback like

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“They showed up fast and had us moving without a tow.”

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“Honest pricing and professional diesel techs.”

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“Best breakdown help on I-10—hands down.”

FAQs

  • Do you repair trucks on the roadside?

    Yes—we handle most breakdowns on-site.

  • Can you tow my truck?

    Yes—we provide light, medium, and heavy-duty towing.

  • Can you diagnose check-engine lights remotely?

    We bring full diesel scan tools to you.

  • Do you repair transmissions and clutches?

    Yes—onsite when possible or at our shops.

  • Do you support fleets?

    Yes—maintenance programs are available.

Call Now for Emergency Truck Repair

📞 Breakdown? Call now for 24/7 dispatch—we come to you.

Fast roadside repairs, expert diesel service, and towing anytime.