Advanced Diesel Engine & System Services

At Decker 24 HR Truck & Trailer, Inc., we know your diesel engine is more than just machinery; it’s the powerhouse that keeps your business moving. Every hour a truck sits idle means lost time, missed deliveries, and added costs. That’s why our diesel repair and maintenance services are designed for speed, accuracy, and reliability.

Serving a 50-mile radius around Belvidere, IL, including Rockford, Rochelle, Huntley, DeKalb, Dixon, Woodstock, and Algonquin, IL, as well as Janesville and Waller, WI, we bring decades of expertise to every repair. As a family-owned and locally operated company, we treat every customer like part of our team and take pride in keeping your fleet on the road where it belongs.

Complete Diesel Engine Diagnostics

Modern diesel engines require precision diagnostics to uncover the root cause of performance issues. Our team uses state-of-the-art computer scanning tools, combined with expert mechanical evaluation, to detect problems early.
We inspect fuel injectors, turbochargers, EGR systems, DPF filters, and electronic controls for accuracy and performance. Whether your truck is losing power, struggling with fuel efficiency, or producing excessive exhaust, we locate the exact issue, not just the symptom.

After diagnostics, we explain repair options clearly, ensuring you always understand what’s being done and why. Transparency and trust are the cornerstones of every job we complete.

Professional Diesel Repair & Rebuilds

From minor adjustments to full engine rebuilds, our skilled technicians handle it all. We service cylinder heads, timing systems, gaskets, and valve trains using industry-standard techniques and OEM-quality parts. Our rebuilds restore compression, fuel economy, and reliability for trucks that have logged serious miles.

Each engine rebuild is carefully measured, inspected, and calibrated before leaving our shop. Whether it’s an injector replacement, turbo upgrade, or internal overhaul, we guarantee precision workmanship designed to keep your diesel performing like new.

Exhaust, Fuel & Cooling System Service

Your truck’s reliability depends on more than just the engine block. Our diesel specialists repair and maintain essential support systems, ensuring every component performs at its best.
Our services include:

  • Fuel System Service: Cleaning, replacing, or rebuilding fuel tanks, injectors, and lines to prevent clogs, leaks, or contamination.
  • Cooling System Repair: Inspecting and rebuilding radiators, water pumps, and intercoolers to prevent overheating and maintain stable operating temperatures.
  • Exhaust & Emission Maintenance: Servicing EGR, DEF, and DPF systems for maximum performance and full environmental compliance.

Our comprehensive approach ensures your diesel runs cooler, cleaner, and longer—delivering the consistent power your routes demand.

Preventive Diesel Maintenance Programs

The best repair is the one you never need. That’s why we offer tailored preventive maintenance programs for individual trucks and fleets.
Our service plans include regular oil and filter changes, sensor calibrations, fuel system treatments, and coolant checks. Each program is designed to match your vehicle’s mileage, duty cycle, and manufacturer recommendations.

By scheduling consistent maintenance, you prevent breakdowns, reduce operating costs, and extend the life of your engine, saving money and downtime in the long run.

Experience You Can Depend On

Decker 24 HR Truck & Trailer, Inc., isn’t a national chain, we’re your local partner in keeping heavy-duty trucks running strong. With over 30 years of diesel repair experience, we’ve earned the trust of drivers and fleet managers throughout Illinois and southern Wisconsin.

We’re insured, certified, and available for emergency calls, because we understand breakdowns don’t follow business hours. Every repair, rebuild, or diagnostic we perform is guided by our core values: quality, urgency, and accountability.

When your diesel truck needs expert care, you can count on Decker 24 HR Truck & Trailer, Inc., to deliver dependable results every time.

Schedule Your Diesel Service Today

Don’t wait for small issues to turn into major repairs. Contact Decker 24 HR Truck & Trailer, Inc., today to schedule your diesel diagnostic, maintenance, or rebuild service. Our team is ready to get your trucks back on the road—performing efficiently, safely, and with the power your business depends on.

Keep your diesel running strong by calling (847) 481-9851 today!