Fleet maintenance for the shops, trucks, and vans keeping Denver moving.
Updated September 30, 2026
Don's Garage Automotive and Transmission has been keeping work vehicles on the road in north Denver since 1970. Three generations of mechanics, located right in the I-70/I-25 industrial corridor — minutes from Globeville, Elyria-Swansea, Cole, and Commerce City. We specialize in transmission and drivetrain work, the repairs that take other shops out for a week and yours out for a day.
Why fleet managers choose Don's.
We're physically where your trucks are.
5515 Washington Street puts us inside the I-70/I-25 industrial corridor — the same corridor where most north Denver fleets operate. If your shop is in Globeville, Elyria-Swansea, Cole, or Commerce City, you're 5-15 minutes away. Drop a truck off in the morning, pick it up the same day. No more shuttling vehicles across town to a strip-mall mechanic.
Transmission specialty — the repair that takes everyone else a week.
Transmission failure on a work truck is the worst kind of downtime. A general repair shop has to send the unit out, wait for parts, wait for a slot. We rebuild transmissions in-house, three generations deep. Family-owned since 1970, transmission specialty since the start. We know the failure modes for the most common fleet vehicles — Ford Transit, F-250/350, Sprinter, ProMaster, Silverado, Express vans. The work that takes other shops a week takes us 3-5 days, and we'll tell you straight whether a rebuild or a replacement is the right call before we start. See our fleet transmission and drivetrain guide for what actually fails on fleet vehicles, duty-cycle service intervals, and what to train your drivers to report.
We've been here for 50+ years. We'll be here when your warranty work needs us.
Family-owned since 1970, three generations of mechanics, same location. Fleet managers planning multi-year vehicle budgets need shops that are still going to be in business when the warranty claim happens. We will be.
What we do for fleet customers.
Don's services the most common fleet vehicle classes — gasoline and diesel, half-ton through one-ton, vans, pickups, box trucks, and specialty service vehicles. Light-duty and medium-duty work trucks are our wheelhouse. Heavy-duty Class 7-8 over-the-road tractors are outside our scope — for those, we'll point you to a heavy-duty specialist.
Fleet vehicles we work on include the Ford F-150, Chevrolet Silverado 1500, GMC Sierra 1500, Toyota Tacoma, Ford F-250, Ram 1500 and Toyota Tundra.
Transmission and drivetrain.
The specialty. Rebuilds, fluid services, torque converter work, transfer case repair, differential service, axle work. The repairs most fleet operators dread because they signal a major bill — handled in-house, faster than typical, with options explained before the work starts.
Engine repair and replacement.
Diagnostics, repairs, full engine replacement when needed. Cooling system work, fuel system service, electrical diagnostics, sensor work. Most engine issues come down to repair or replacement, and we handle both end-to-end.
Brake systems.
Pads, rotors, calipers, lines, master cylinders, ABS work. Critical for any work vehicle, especially one that's loaded down all day.
Suspension and steering.
Shocks, struts, ball joints, tie rods, alignments. Work trucks beat their suspension. We see it constantly.
Preventive maintenance.
Oil changes, transmission services, coolant flushes, brake fluid changes, differential services. Scheduled by mileage interval for each vehicle in your fleet. The math on PM is brutal: $300 in fluid changes prevents a $4,000 transmission failure six months later. We can build a maintenance schedule for your specific fleet vehicles and remind you when each is due. See our fleet maintenance schedule by vehicle class for the severe-duty intervals we recommend across the most common fleet vehicles.
Diagnostics and pre-purchase inspections.
If you're considering adding a used truck to the fleet, we'll inspect it before you sign anything. Bring it by, we put it on the lift, you get a written report on its actual condition. Avoid buying someone else's problem.
How fleet relationships actually work here.
Fleet customers care about predictable processes, not slogans. Here's what to expect when you work with us.
Single point of contact.
Whoever books the work for your first truck can keep handling your account whenever possible. They get to know your vehicles, your schedules, your preferences. Fleet managers don't want to re-explain their operation every time a truck comes in.
Transparent communication.
When a truck comes in, we'll call with the diagnosis before we start work — with the price, the timeline, and the options. If we find more during the work, we call you again. No surprise bills.
Scheduled service slots.
If you can plan PM in advance, we can schedule it during slower windows so your trucks aren't waiting for service bays. We can prioritize fleet booking when you need it.
Records you can use.
Every service comes with itemized documentation — what was done, what parts, what labor, mileage at service, recommendations for next visit. Useful for your fleet records, useful for resale value when you eventually rotate the vehicle out.
No surprises pricing.
We can't quote a transmission rebuild without putting it on the lift. But we'll give you the worst-case quote before we start — you'll know the upper bound, and we'll only charge that if we hit the worst-case scenario. Most jobs come in under.
Vehicle classes we work on.
We focus on the work-vehicle classes fleet operators actually run — light-duty and medium-duty, gas and diesel.
- Cargo vans: Ford Transit, Mercedes Sprinter, RAM ProMaster, Chevrolet Express, GMC Savana
- Light-duty pickups: Ford F-150, Chevy Silverado 1500, RAM 1500, Toyota Tacoma, Toyota Tundra
- Heavy-duty pickups: Ford F-250 / F-350, Chevy Silverado 2500/3500, RAM 2500/3500
- Box trucks and cube vans up to medium-duty
- SUVs used as fleet vehicles: Suburbans, Tahoes, Expeditions
- Service vehicles: contractor pickups, plumbing trucks, HVAC vans, electrician vans, landscaping trucks
- Sedans and compact vehicles for sales fleets
Heavy-duty Class 7-8 over-the-road tractors are outside our scope. Everything below that, we handle.
The real cost of downtime.
Most fleet operators only count the repair bill when a vehicle goes down. The actual cost is much higher.
Industry research from Element Fleet puts daily downtime cost at $448 to $760 per vehicle, depending on the use case. That includes lost revenue, driver wages paid for nothing, rental replacement vehicles, missed delivery penalties, and the labor your dispatch puts into rerouting around the missing truck. A single truck out for a week is $2,200 to $3,800 in true cost — on top of whatever the repair itself is.
The math on preventive maintenance changes when you count downtime correctly. A $300 transmission fluid service prevents a $4,000 rebuild AND saves you 5-7 days of downtime — easily another $2,500-$5,000 in real cost. Spending $300 to prevent $6,000+ is a no-brainer when you do the math right.
We help fleet customers do the math right. Ask us about a maintenance schedule for your specific vehicles — we can tell you what's likely to fail at what mileage, what the prevention costs versus the failure costs, and which interventions have the best return.
Want to run your specific numbers? Use our free fleet downtime cost calculator — it'll show you what downtime is actually costing your fleet annually based on your fleet size, daily revenue per vehicle, and current downtime days.
Where we serve fleet customers.
5515 Washington Street is in the heart of north Denver's industrial corridor. We routinely serve fleet customers from Globeville, Elyria-Swansea, Cole, the Five Points area, Commerce City, the I-70 corridor east, and the I-25 corridor north. If your fleet operates within 15 miles of our shop, you're in our regular service zone.
Fleet customers running CDL or non-CDL commercial vehicles can also reference our DOT inspection readiness checklist for what to keep ready between inspections.
Let's talk about your fleet.
If you're managing 5-50 vehicles and tired of the back-and-forth with shops that don't know your trucks, give us a call. We'll come out and look at your fleet, talk through what you've got, and figure out whether we're the right shop for the work. No commitment, no hard sell. The first conversation is just two parties figuring out if we make sense for each other.
Truck down right now? See what to do first.
Where the fleet work lives.
Our transmission specialty
Where 50+ years of focus translates directly into fleet uptime.
See transmission services →
Fleet vehicle nearing end of life?
Run the math on whether to keep fixing it or rotate it out.
Use the calculator →
Drop by the shop
5515 Washington Street, Denver. We're easy to find — right off I-70.
Get directions →Fleet questions we get most.
What does fleet maintenance cost?
Fleet maintenance cost depends on vehicle class, mileage, and service intervals. Standard preventive maintenance for a light-duty work van or pickup typically runs $200-$600 per service interval. Major repairs like transmission rebuilds run $2,200-$4,000 for domestic and Japanese vehicles. The bigger cost most fleet operators miss is downtime — industry research puts vehicle downtime at $448-$760 per day. Preventive maintenance is almost always far cheaper than reactive repair when downtime is counted correctly.
How do I find a good fleet repair shop in Denver?
Look for proximity to where your fleet operates, specialty depth in transmission and drivetrain work (the highest-cost failures), longevity (so the shop will be there for warranty work), single-point-of-contact account handling, and transparent quoting practices. Don's Garage at 5515 Washington Street in north Denver fits all five — we've been family-owned since 1970, transmission is our specialty, and we're located in the I-70/I-25 industrial corridor where many Denver fleets operate.
What's the real cost of fleet vehicle downtime?
Industry research from Element Fleet puts vehicle downtime at $448 to $760 per day per vehicle, depending on the use case. That includes lost revenue, driver wages paid during downtime, rental replacement vehicles, missed delivery penalties, and dispatch labor for rerouting. Most fleet operators only count the repair bill — the true cost of a week-long downtime is typically $2,200-$3,800 on top of the repair, which fundamentally changes the math on preventive maintenance.
Can a small repair shop handle a 20-truck fleet?
Yes — and a small specialty shop is often a better fit than a chain or dealer for fleets in the 5-50 vehicle range. Smaller shops offer single-point-of-contact account handling, faster turnaround on common repairs, transparent quoting, and direct relationships with the technicians actually doing the work. Don's Garage handles fleet customers across north Denver from a single location with three generations of mechanics on staff.
What vehicle classes does Don's Garage service for fleet customers?
We service cargo vans (Ford Transit, Mercedes Sprinter, RAM ProMaster, Chevrolet Express, GMC Savana), light-duty pickups (F-150, Silverado 1500, RAM 1500), heavy-duty pickups (F-250/F-350, Silverado 2500/3500, RAM 2500/3500), box trucks and cube vans up to medium-duty, fleet SUVs (Suburban, Tahoe, Expedition), service vehicles for contractors, plumbers, HVAC, and electricians, and sedans/compact vehicles for sales fleets. Heavy-duty Class 7-8 over-the-road tractors are outside our scope.
How do I set up a fleet maintenance schedule?
Most fleets run preventive maintenance on mileage-based intervals tailored to each vehicle class. Oil changes typically every 5,000-7,500 miles for gas, 10,000-15,000 for diesel. Transmission services every 30,000-60,000 miles depending on duty cycle. Coolant flushes every 60,000-100,000. Brake services as needed based on wear. We can build a maintenance schedule for your specific fleet vehicles and remind you when each is due — bring your fleet by and we'll work it out together.
Do you do pre-purchase inspections for used fleet vehicles?
Yes. If you're considering adding a used truck or van to your fleet, bring it by before you sign anything. We put it on the lift, run diagnostics, check the major systems, and give you a written report on its actual condition. The cost of an inspection is a fraction of the cost of buying a vehicle that needs $4,000 in immediate repairs.
What makes Don's Garage different for fleet customers?
Three things: location (we're in the I-70/I-25 industrial corridor where most north Denver fleets operate, so drop-off and pickup are short trips), specialty (transmission and drivetrain work is our wheelhouse, which is the most expensive and most disruptive failure for fleet vehicles), and longevity (family-owned since 1970, three generations of mechanics, same location — the shop will still be here when warranty work is needed).
Where in Denver is Don's Garage located?
Don's Garage Automotive and Transmission is at 5515 Washington Street in Denver, Colorado 80216. We're in the heart of the north Denver industrial corridor between I-25 and I-70 — minutes from Globeville, Elyria-Swansea, Cole, and Commerce City.
Do you service fleet vehicles in Commerce City?
Yes. Commerce City is one of our core service areas — we're just across the I-70 corridor from most Commerce City addresses. A few miles up Quebec, Vasquez, or Brighton from our shop. Many Commerce City fleet customers run light-duty and medium-duty work vehicles in industrial and contractor businesses, which is exactly the work we specialize in.
How do I get started as a fleet customer at Don's Garage?
Call (303) 295-2448. We'll set up an initial conversation — either over the phone or by visiting your fleet on-site. We talk through what you've got, what your maintenance pattern looks like, and figure out whether we're the right shop for the work. No commitment, no hard sell. The first conversation is just both sides figuring out if it makes sense.
What's the difference between fleet repair and regular auto repair?
Fleet repair prioritizes uptime and predictable cost over individual-customer convenience. Fleet customers want fast turnaround, scheduled PM windows, single-point-of-contact account handling, transparent worst-case quoting, and itemized records useful for fleet management. Retail auto repair tends to be more reactive — customer comes in with a problem, gets a quote, decides whether to fix. Fleet relationships are proactive partnerships: the shop knows the vehicles, schedules the maintenance, and helps the fleet manager budget for future failures.
Ford Transit fleet maintenance schedule — what intervals?
Transit vans in fleet duty hit transmission service requirements faster than retail intervals. We recommend transmission service every 30,000-40,000 miles for medium-duty Transit fleets, every 50,000 for light-duty. Engine oil every 5,000-7,500 miles depending on idle time. Brake service typically at 50,000-70,000 miles for delivery routes. Call us to build a fleet-specific schedule.
Mercedes Sprinter fleet service Denver?
Sprinters in fleet duty need diesel-specific attention — fuel filter every 20,000 miles, transmission service every 30,000, def system maintenance per manufacturer spec. Most fleet Sprinters we service are 2014+ with the OM651 diesel; common issues include glow plug failure (~80,000 miles) and turbo actuator wear. We can coordinate scheduled maintenance so trucks rotate through during slower fleet operating windows.
F-250 / F-350 fleet — what services matter most?
Heavy-duty F-Series in fleet duty live or die on service discipline. Transmission service every 30,000 miles flat. Diesel oil and fuel filter changes per Powerstroke spec (or sooner under high-idle service truck duty). Front-end suspension work is constant on plow trucks and heavy-haul fleets. We service dozens of F-250/F-350 platforms — bring yours in for a baseline assessment.
Chevy Silverado 1500 fleet maintenance?
Silverado 1500 light-duty fleet vehicles (sales fleets, supervisor trucks) are among the most reliable platforms when serviced consistently. Typical fleet schedule: oil every 5,000-7,500 miles, transmission service every 50,000-60,000, brake service every 40,000-60,000, suspension work as needed. Most Silverado 1500s in light-duty fleet use hit 250,000 miles before major drivetrain repair becomes likely.
RAM ProMaster fleet vans — common issues?
ProMasters are FCA's commercial van platform; we see them mostly in delivery and contractor fleets. Common service items: 9-speed transmission service (critical — these wear faster than older 6-speeds), front strut wear from heavy front-end loading, electrical gremlins around the body control module on high-mileage units. Service every 30,000 miles transmission, 50,000 brakes, 60,000 suspension assessment.
Chevy / GMC Express / Savana fleet vans?
The Express / Savana platform is a fleet workhorse with the 6L90 transmission and either 4.3L V6 or 6.0L V8 gas engines. Fleet customers typically run these to 250,000+ miles with proper service. Transmission service every 50,000 miles, brake service every 50,000-70,000, suspension work as the fleet ages. Don's services Express/Savana fleets across north Denver delivery and contractor companies.
Heavy-duty 2500/3500 diesel fleet — Cummins, Powerstroke, Duramax?
Each diesel platform has its own quirks. Cummins (RAM HD): rock-solid block but transmission and front-end need attention. Powerstroke (Ford): 6.7L modern variants are reliable when fluid services are strict; the EGR/DPF systems need attention in fleet idle duty. Duramax (Chevy/GMC): Allison transmissions are bulletproof when serviced; injectors are the common high-mileage failure point. Each requires specific maintenance schedules — call us to talk through your specific fleet mix.
Do you offer net 30 billing for fleet accounts?
Yes. Fleet accounts can be set up on net 30 terms, so your drivers can drop off a vehicle and get back to work without settling up at the counter. Ask about opening an account when you schedule your first vehicle or your free fleet audit.
When is payment due?
Fleet accounts on net 30 get an invoice and 30 days to pay. Without a net 30 account, payment is due when you pick up the vehicle.
Can we drop off more than one vehicle at a time?
Yes. Fleets can drop off several vehicles at once. A quick call ahead helps us plan the shop around them.
Fleet maintenance you can actually plan around.
Family-owned in north Denver since 1970, three generations of mechanics. Drop us a call to talk about your fleet — no commitment, no hard sell.