Diesel Truck Repair in Glasgow, MT
Expert Diesel Diagnostics and Repairs That Keep You Running
When your diesel truck needs repairs, you need a shop that understands diesel power from the inside out. At Thompson & Sons Inc., we provide full-service diesel truck repair in Glasgow, MT for drivers, fleet managers, and heavy-duty operators who depend on performance and uptime.
Our family-owned shop is equipped to handle everything from routine maintenance to complex engine diagnostics and repairs. Whether you drive a diesel pickup, semi-truck, or heavy-duty vehicle, we deliver accurate service with fast turnaround to keep your operation on track.
Diesel Repair Services We Offer
Our diesel technicians bring years of experience and a deep understanding of diesel engines, fuel systems, and emissions control technologies. We service all major brands, including Cummins, Duramax, Power Stroke, Detroit Diesel, Caterpillar, and more.
Services include:
Computer diagnostics
Turbocharger repairs
EGR, DPF, and DEF system service
Fuel injector replacement
Cylinder head and gasket repairs
Cooling system repairs
Oil and fluid leaks
Engine rebuilds and replacements
Emissions troubleshooting
Scheduled diesel maintenance
If you’re seeing check engine lights, experiencing low power, or burning through fuel faster than usual, don’t wait. Our shop can quickly pinpoint the issue and get it resolved the right way — without unnecessary downtime or costly guesswork.
Mobile Diesel Truck Repair
Breakdowns don’t always happen near a shop — and that’s why we come to you. Thompson & Sons Inc. offers mobile diesel repair services throughout northeast Montana.
Our mobile units are fully stocked with tools and diagnostic equipment to handle most diesel issues on-site. Whether you’re stranded on the highway, at a job site, or in your yard, we’ll bring fast, reliable repairs to your location.
Mobile diesel services include:

- Roadside diagnostics
- Battery and starter replacement
- Fuel system repairs
- Sensor replacements
- On-site fluid service
- Engine troubleshooting
- Minor component installs
If the issue can’t be resolved on the spot, we’ll help arrange towing back to our shop for more in-depth repair.
Fleet Diesel Maintenance
Running a diesel fleet means you can’t afford breakdowns or unexpected repair bills. We provide scheduled diesel maintenance programs for businesses, contractors, and agricultural operations throughout Valley County and beyond.
Benefits of a fleet program:
Scheduled service intervals based on mileage or hours
DOT inspections and compliance support
Preventive checks for fuel, cooling, and brake systems
Full record-keeping and service history
Faster turnaround and priority scheduling
From delivery vehicles to farming trucks and commercial fleets, we help businesses keep their equipment safe, efficient, and on the road.
Common Diesel Problems We Fix
Not sure what’s wrong with your truck? These are some of the most common diesel issues we diagnose and repair:
Rough idle or hard starting
Excessive black or white smoke
Turbo lag or boost loss
Overheating under load
Loss of fuel efficiency
DEF system warning lights
Unresponsive throttle
Intermittent power loss
DPF regen failure
Our technicians use dealer-grade scan tools and proven diagnostic methods to isolate the problem and recommend solutions that make sense — both mechanically and financially.
Diesel Repairs for All Applications
We work on a wide range of diesel-powered vehicles and equipment, including:
Diesel pickups (Duramax, Cummins, Power Stroke)
Class 8 trucks and semis
Heavy-duty work trucks
Dump trucks and gravel haulers
Dozers and agricultural equipment
Diesel generators and pumps
Whether your engine has 50,000 or 500,000 miles, we treat it with the care and attention it deserves.
Why Choose Thompson & Sons Inc.
When it comes to diesel repair, you need more than just a basic mechanic. Our customers choose us because we combine technical skill with personal service — and we back every repair with integrity.
What makes us different:
Decades of diesel experience
Family-run shop that puts customers first
Clean, well-equipped facility for heavy-duty repair
Mobile service for fast roadside support
Straightforward pricing and honest advice
Located right here in Glasgow, MT
We understand how critical your diesel truck is to your work. Our job is to keep it running right — and to get you back behind the wheel as quickly and safely as possible.
Schedule Diesel Service Today
Don’t let small diesel issues turn into costly failures. Whether you need a quick fix or a complete engine overhaul, Thompson & Sons Inc. has the tools, training, and team to get the job done.
Call today to schedule service, request a mobile visit, or ask about our fleet programs.
Phone:
(406) 228-4801
Email:
thompsonmandsons@nemont.net
Shop: 53997 Highway 2 West, Glasgow, MT 59230
Hours: Monday–Friday, 8 am to 12 pm and 1 pm to 5 pm
We’re proud to be Glasgow’s trusted diesel truck repair shop — and we look forward to earning your business.