Diesel Repair

Expert Diesel Repair for Trucks, Fleets & RVs

From diagnostics to complete rebuilds, we deliver quality diesel repair services with fast turnaround times and transparent communication.

Expert Diesel Repair Without the Pricey Guesswork.

Diesel engines are complex, powerful, and expensive to operate. When something goes wrong, you need accurate diagnostics and quality repairs—not guesswork and unnecessary replacements.

OKC Fleet Services specializes in diesel repair for commercial trucks, fleet vehicles, and diesel-powered RVs. Our experienced technicians use advanced diagnostic equipment to identify issues quickly and perform repairs that last.

Our Diesel Repair Services

We provide expert diesel care, covering everything from advanced computer diagnostics and fuel system repair to complete engine rebuilds. Our technicians specialize in turbochargers, transmissions, and complex aftertreatment (DPF/SCR) systems to restore your power and efficiency with zero guesswork.

Diesel Engine Diagnostics

Advanced diagnostic tools for all diesel makes and models. We identify the root cause quickly so you get accurate estimates and no surprises.

Engine Repair

From fuel system issues to cooling system problems, we handle all diesel engine repairs with precision and quality parts.

Engine Rebuilds

In-frame engine overhauls available for medium and heavy-duty diesel engines.

Engine Replacements

We provide complete engine replacement solutions. We help you evaluate repair vs. replacement, source the right engine, and install it correctly to get your vehicle back in service as quickly and efficiently as possible.

Fuel System Service

Fuel injector testing, replacement, and calibration. High-pressure fuel pump repair. Complete fuel system diagnostics and repair.

Turbocharger Service

Turbo diagnostics, repair, and replacement. We restore power and efficiency to your diesel engine.

Cooling System Repair

Radiator repair and replacement, water pump service, thermostat replacement, and complete cooling system diagnostics.

Aftertreatment Systems

DPF (Diesel Particulate Filter) cleaning and replacement, DOC (Diesel Oxidation Catalyst) service, SCR (Selective Catalytic Reduction) repair, DEF system diagnostics and repair.

Electrical & Computer Diagnostics

Modern diesel engines rely on complex computer systems. We diagnose and repair electrical issues, sensor failures, and computer system problems.

Transmission Services

Transmission diagnostics, repair, and complete replacement services for manual and automatic transmissions.

Brake System Repair

Air brake service and repair, hydraulic brake systems, brake inspections, and complete brake system overhauls.

Makes We Service

We service all major diesel truck, fleet, and RV chassis manufacturers, including:

And More..

The OKC
Fleet Services Process

Fast Diagnostics

Drop off your vehicle or call for service. We complete diagnostics within one business day using advanced diagnostic equipment.

Clear Estimates

We provide detailed estimates within the following half business day of completing diagnostics. You’ll know exactly what needs repair and what it will cost.

Quality Repairs

Once approved, our experienced technicians perform repairs using quality parts and proper procedures. No shortcuts.

Daily Updates

We provide daily status updates so you always know where your repair stands.

Final Inspection

Before delivery, every vehicle undergoes a final quality inspection to ensure the repair meets our standards.

Why Choose
OKC Fleet Services?

OKC Fleet Services provides expert diesel repairs using advanced diagnostics and quality parts to ensure your fleet stays on the road. We are committed to transparent communication and fast turnaround times that minimize downtime without ever sacrificing craftsmanship. From diagnostics to repairs and preventive maintenance, our services are designed to keep your trucks reliable, efficient, and ready for the road.

Experienced Technicians

Our team has the training and experience to handle complex diesel repairs on all makes and models.

Advanced Equipment

We invest in the latest diagnostic tools and equipment to provide accurate diagnostics and quality repairs.

Quality Parts

We use OEM or quality aftermarket parts—never cheap alternatives that fail prematurely.

Transparent Communication

No surprises. We call before performing any work beyond your approved estimate.

Fast Turnaround

We understand downtime costs money. We work efficiently without sacrificing quality.

Service Area

We serve diesel truck owners, fleet operators, and RV owners throughout the
Oklahoma City metro area, including

4.9 out of 5 Stars on Google

Don’t just take our word for it — hear from fleet managers who trust us daily.

 
 
 
 
 
 
 
  
 
 
 
 Posted on Google Google 
 
 Matthew James profile picture 
 
 
 Matthew James 
 
 
 
 Google star 1Google star 2Google star 3Google star 4Google star 5Trustindex verifies that the original source of the review is Google. 
Guys had me come out and detailed all there vehicles I would highly recommend this company for all of there services very genuine people give them a five star rate they are the best
  
 
  
 
 
 
 Posted on Google Google 
 
 Jake Floresca profile picture 
 
 
 Jake Floresca 
 
 
 
 Google star 1Google star 2Google star 3Google star 4Google star 5Trustindex verifies that the original source of the review is Google. 
OKC Fleet Services is an extremely dynamic company to work with.  They not only coordinated the tow/delivery within an hour of me calling but repaired everything the next day to get my truck back on the road.  I cannot recommend this company enough.  Shout out to Lacey for being spectacular keeping me updated and handling my situation with ease.
  
 
  
 
 
 
 Posted on Google Google 
 
 Mr Christian profile picture 
 
 
 Mr Christian 
 
 
 
 Google star 1Google star 2Google star 3Google star 4Google star 5Trustindex verifies that the original source of the review is Google. 
Very professional team..!! Excellent customer services..!!! Reasonable prices..!! 5 ⭐️ they fixed my truck that other shop couldn’t..
  
 
  
 
 
 
 Posted on Google Google 
 
 Scott Jones profile picture 
 
 
 Scott Jones 
 
 
 
 Google star 1Google star 2Google star 3Google star 4Google star 5Trustindex verifies that the original source of the review is Google. 
Honest, friendly kept me informed and stuck to the pricing agreed on. We will go back.
  
 
  
 
 
 
 Posted on Google Google 
 
 Christian Krogman profile picture 
 
 
 Christian Krogman 
 
 
 
 Google star 1Google star 2Google star 3Google star 4Google star 5Trustindex verifies that the original source of the review is Google. 
We recently transitioned our company maintenance program to OKC Fleet Services, and the experience has been outstanding. They service our semis promptly, their technicians consistently provide excellent work, and our sales manager, Bree, has been exceptional. Thank you from the entire Ironclad team!
  
 
  
 
 
 
 Posted on Google Google 
 
 Patrick Earles profile picture 
 
 
 Patrick Earles 
 
 
 
 Google star 1Google star 2Google star 3Google star 4Google star 5Trustindex verifies that the original source of the review is Google. 
I was in Guthrie, Oklahoma when I had a turbocharger failure on my Peterbilt. I contacted Garrett and he was able to source the parts I needed quickly. He dispatched John to my location where John was able to remove my intercooler and piping from my truck and take it back to their shop for cleaning and inspection. John returned and installed the turbo, intercooler and piping and had me back up and running with minimal downtime. I  highly recommend OKC Fleet Services. Garrett and John were not only friendly, but very professional and highly knowledgeable. Their tools and equipment are second to none. When you hire them you know that you are getting a quality job from quality people
  
 
  
 
 
 
 Posted on Google Google 
 
 Ray Burgman profile picture 
 
 
 Ray Burgman 
 
 
 
 Google star 1Google star 2Google star 3Google star 4Google star 5Trustindex verifies that the original source of the review is Google. 
My dash air in my RV was not working. I arrived at OKC FLEET SERVICE about 4:15 pm. They kept my RV overnight. About 9:30 am the next morning they called and had my problem diagnosed and gave me a price to repair it. Less then an hour later they called and said I could come and pick it up. They were very professional and I would recommend them.
  
 
  
 
 
 
 Posted on Google Google 
 
 Cody Wright profile picture 
 
 
 Cody Wright 
 
 
 
 Google star 1Google star 2Google star 3Google star 4Google star 5Trustindex verifies that the original source of the review is Google. 
We’ve had multiple kinds of service done for our fleet, and the staff has been great to work with and the techs have done great work

Best of OKC

2024, 2025 & 2026 Award Winner

NAPA Certified

Truck Care Center

FAQ for Diesel repair

Quick answers to common questions about our services and processes.

1

What diesel engine services do you offer?

Full diagnostics, repair, and replacement services for diesel engines across all major manufacturers and truck types.

2

Can you work on any engine brand?

Yes — we service diesel engines across the brands we support, including Cummins, Powerstroke, Duramax, and major Class 8 truck manufacturers.

3

How long does a typical engine repair take?

Diagnostics are completed within one business day, with an estimate delivered within the following half day. Once parts arrive and repairs are approved, work begins within a half day. Exact repair time depends on the scope of the issue.

4

Do you use OEM parts for engine repairs?

We use quality parts and proper procedures that meet manufacturer specifications, so repairs are done right the first time and hold up long-term.

5

What are signs my diesel engine needs service?

Loss of power, excessive smoke, unusual noises, fault codes, poor fuel economy, or hard starting are all signs it’s time for a diagnostic check.

Get Your Diesel
Truck Back on the Road

Fast diagnostics. Quality repairs. Transparent pricing.
24hr Diagnostics
Daily Updates
Quality Guaranteed