At McCallon’s Diesel Services, we provide comprehensive diesel truck and trailer repair solutions designed to keep you on the road and minimize costly downtime. Whether you need routine maintenance, complex diagnostics, or emergency roadside help, our team has the tools, experience, and dedication to get the job done right.
Engine Diagnostics & Repair
From minor tune-ups to complete overhauls, our certified diesel mechanics specialize in pinpointing and repairing engine issues. Using advanced diagnostic equipment, we quickly identify problems and deliver reliable solutions to keep your engine performing at its best.
Transmission & Drivetrain
Your truck’s transmission and drivetrain are critical for performance and fuel efficiency. We handle everything from fluid service and clutch repair to complete transmission rebuilds, ensuring smooth operation and long-term reliability.
Electrical & Lighting
Electrical problems can leave you sidelined and frustrated. Our team is skilled in diagnosing and repairing electrical systems, wiring, batteries, alternators, and lighting—keeping your truck safe, compliant, and road-ready.
Brakes & Suspension
Safe stopping power and a dependable suspension system are essential for heavy-duty hauling. We provide brake inspections, replacements, suspension repairs, and upgrades to keep your truck stable and safe on every haul.
DOT Inspections
Stay compliant and avoid unexpected downtime with our thorough DOT inspections. We make sure your truck and trailer meet all federal regulations and requirements so you can drive with confidence.
Trailer Repair
From structural issues to lighting, brakes, and axles, we offer full-service trailer repair. Our goal is to keep your trailers safe, reliable, and ready to handle heavy loads.
Fleet Maintenance
Managing a fleet requires a trusted partner. We provide preventative maintenance programs tailored to your schedule and needs, helping you reduce breakdowns, extend vehicle life, and improve operational efficiency.
Heating & A/C Services
Driver comfort matters—especially during extreme Midwest weather. We offer complete heating and A/C repair and maintenance services so you can stay comfortable behind the wheel year-round.
Emergency Roadside Assistance
Breakdowns don’t keep business hours—and neither do we. Our 24/7 emergency roadside assistance ensures you’re never stranded for long. Whether it’s engine trouble, electrical failure, or a flat, our team will get you back on the road quickly.
Why Choose McCallon’s Diesel?
✔ Serving the St. Louis Metro, St. Charles County, Lincoln County & Warren County
✔ Certified diesel mechanics with years of hands-on experience
✔ Fast, honest, and dependable service
✔ 24/7 emergency roadside assistance
McCallon’s Diesel Services—keeping your trucks, trailers, and fleets moving when it matters most.