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Truck preventive maintenance: a schedule you can prove

A truck that runs fine today can still fail a roadside inspection or an audit. Preventive maintenance is the schedule that keeps parts from failing, and the record that shows the work was done.

Truck maintenance in numbers

12 moLongest gap between annual inspections
3 moKeep each DVIR and repair certification
1 yrKeep maintenance records, plus 6 months after the unit leaves
21.5 ¢/miAverage repair and maintenance cost in 2025
Sources: 49 CFR 396.3, 396.11, and 396.17; ATRI's 2026 Operational Costs update, as reported by The Trucker.

Truck preventive maintenance is the scheduled inspection, servicing, and repair of trucks and trailers before parts fail. Under 49 CFR 396.3, every motor carrier must systematically inspect, repair, and maintain the vehicles it controls, track what is due and when, and keep records that prove the work was done.

When a maintenance problem turns into a violation, the cause is usually a missed due date or a defect nobody closed out, not a shortage of mechanics.

I lead operations at Simplex, and I treat preventive maintenance as a system with three parts: a schedule, a loop that turns every reported defect into a repair, and a record that proves both.

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7 chapters. Select one to jump to it.

01Maintenance you can prove
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Generated with AI text-to-speech from this article's key insights, in order, rather than reading it word for word. Chapter times come from a transcript of the audio. The article itself was written and reviewed by Inely Baez.

Technician greasing the front steering components of a semi-truck tractor in a maintenance bay
The rule sets no mileage interval. It requires a schedule you set, and a record that each visit happened.
The Short Version

Key takeaways

The rule requires a system, not a mileage interval

49 CFR 396.3 requires systematic inspection, repair, and maintenance, plus a way to show the nature and due date of each task. You set the intervals.

Drivers close the daily loop

A driver who finds or is told of a defect reports it in writing at the end of the day. The carrier repairs it, or certifies no repair is needed, before the vehicle runs again.

Every unit needs an annual inspection

Each tractor, trailer, and converter dolly must pass a periodic inspection at least once every 12 months, with proof on the vehicle.

Each record has its own clock

Maintenance records: 1 year, plus 6 months after the vehicle leaves your control. Annual inspection reports: 14 months. DVIRs: 3 months.

Missed maintenance reaches your CSA scores

Vehicle violations count in the Vehicle Maintenance BASIC for 24 months. Tire violations carry a severity weight of 8 on a scale of 1 to 10.

The Basics

What is truck preventive maintenance?

Truck preventive maintenance, or PM, is maintenance done on a schedule instead of after a breakdown: inspections, lubrication, fluid and filter service, adjustments, and replacing worn parts before they fail. A PM service is one of those scheduled visits.

The federal rule behind it is short. Under 49 CFR 396.3(a), every motor carrier must systematically inspect, repair, and maintain all motor vehicles subject to its control, and keep parts and accessories in safe and proper operating condition at all times.

The rule reaches beyond the equipment list in Part 393, naming frames, suspension systems, axles, wheels and rims, and steering systems. It sets no mileage or day interval. Instead, it requires a means to show the nature and due date of each inspection and maintenance task. In practice, that is your PM schedule.

Why is preventive maintenance important?

  • It is the law. Under 49 CFR 396.7, a vehicle may not be operated in a condition likely to cause an accident or a breakdown.
  • Inspectors find what PM misses. In CVSA's 2026 International Roadcheck, 23.5% of the vehicles given a vehicle inspection were placed out of service, led by brakes and tires.
  • It shapes your safety record. Maintenance violations count in FMCSA's Vehicle Maintenance BASIC for 24 months.
  • Repairs are getting more expensive. ATRI puts repair and maintenance at 21.5 cents per mile in 2025, before tires.
The Rule

What does the DOT require for truck maintenance?

Part 396 of the Federal Motor Carrier Safety Regulations sets the maintenance duties, and a preventive maintenance program is how you meet them. Each section comes with a record and a retention period.

Maintenance duties in 49 CFR Part 396 (eCFR, up to date as of September 22, 2026).
SectionWhat it requiresRecord and how long
396.3Systematic inspection, repair, and maintenance, with a way to track the nature and due date of each taskFor each vehicle controlled 30 consecutive days: 1 year where it is housed or maintained, and 6 months after it leaves your control
396.5Vehicles properly lubricated and free of oil and grease leaksNo separate record
396.11A written driver vehicle inspection report (DVIR) at the end of each day's work when a defect is found or reported; repair or certify before the vehicle runs againDVIR, repair certification, and the driver's review: 3 months
396.13Before driving, the driver is satisfied the vehicle is safe, reviews the last DVIR, and signs it when a defect was listedThe driver's signature on the DVIR
396.17Each vehicle in a combination passes a periodic inspection at least once every 12 months, covering Appendix AThe report, or a sticker or decal based on it, on the vehicle
396.19 and 396.25Annual inspectors and brake inspectors qualified by training, certification, or experienceEvidence of qualifications: while they do the work, plus 1 year
396.21The inspector's report of the annual inspection14 months, where the vehicle is housed or maintained

Exceptions exist. The DVIR rule does not apply to a motor carrier operating only one commercial motor vehicle, and Part 396 does not apply to covered farm vehicles.

Two parts changed in 2026. A rule effective March 23, 2026 states explicitly that DVIRs may be created and kept electronically. A technical rule effective July 21, 2026 dropped tire size from the vehicle identification required in maintenance records.

For the wider set of equipment rules and what belongs in a vehicle file, see our guide to equipment maintenance and DOT regulations.

The Checklist

What belongs on a truck preventive maintenance checklist?

A truck preventive maintenance checklist works in tiers. Federal rules fix the daily and annual tiers. The manufacturer's schedule and your own duty cycle set everything in between.

A tiered truck preventive maintenance checklist, and where each tier comes from.
WhenWhat to checkSet by
Before each tripThe vehicle is in safe operating condition; the last DVIR is reviewed and signed if it listed defects49 CFR 396.13
End of each day's workService brakes and trailer brake connections, parking brake, steering, lights and reflectors, tires, horn, wipers, mirrors, coupling devices, wheels and rims, emergency equipment49 CFR 396.11
Each scheduled PM serviceLubrication and leaks, fluids and filters, brake adjustment, and every item on the manufacturer's service scheduleThe manufacturer, plus 49 CFR 396.3 and 396.5
At least every 12 monthsThe 15 Appendix A categories, for every tractor, trailer, and converter dolly49 CFR 396.17 and Appendix A

The annual inspection in Appendix A to Part 396 covers the brake system, coupling devices, exhaust, fuel system, lighting, safe loading, steering, suspension, frame, tires, wheels and rims, windshield glazing, windshield wipers, motorcoach seats, and the rear impact guard.

Appendix A also sets pass-fail limits, such as the maximum pushrod stroke for each brake chamber type. Using the same limits at every PM service means the annual inspection holds no surprises.

Emergency equipment belongs on the daily list. Our DOT fire extinguisher guide covers the rating and mounting rules.

At Inspection

How do maintenance violations affect your CSA scores?

Violations found in a vehicle inspection feed the Vehicle Maintenance BASIC in FMCSA's Safety Measurement System (SMS). It counts Level 1, 2, 5, and 6 inspections from the past 24 months, including the clean ones.

Severity weights for maintenance violation groups, SMS Methodology Appendix A, version 3.21 (May 2026).
Violation groupSeverity weight (1 to 10)
Operating a vehicle declared out of service10
Tires8
Suspension7
Lighting; steering mechanism6
Brakes; inspection reports, such as a missing DVIR or no proof of a periodic inspection4
Coupling devices; improper lubrication3

An out-of-service violation adds 2 to its weight, and violations from the last six months count three times as heavily as those more than a year old. A carrier at or above the 80th percentile in this BASIC is flagged for intervention (75th for hazmat carriers, 65th for passenger carriers).

Investigators check the program itself. Failing to keep minimum maintenance records, using a vehicle that was not periodically inspected, and failing to require DVIRs are critical violations. Running a vehicle before fixing out-of-service defects a driver reported is an acute one.

At roadside, brakes and tires lead. In CVSA's 2026 International Roadcheck, brake problems made up 39.1% of vehicle out-of-service violations, tires 20.9%, and lights 11.9%. See how CSA scores are built, and what each CVSA inspection level covers.

The Numbers

What does truck maintenance cost?

Repair and maintenance rose 8.6% in 2025, according to ATRI's 2026 Analysis of the Operational Costs of Trucking. Only tolls rose faster in percentage terms.

The average was 21.5 cents per mile, The Trucker reports, covering parts, labor, and roadside service. Tires are tracked separately, at about 5 cents per mile. Preliminary 2026 data showed another 2.4% increase.

ATRI ties part of the rise to older equipment, as carriers hold on to trucks longer. Fleets of five trucks or fewer reported higher costs still, which ATRI credits to many small carriers buying older, used equipment.

An honest caveat. We have not found a savings figure for preventive maintenance that we could verify against a primary source, so we don't quote one. ATRI's numbers also come from participating fleets whose trucks averaged 3.6 years old in 2025. Track your own cost per mile by unit.
Step by Step

How to build a truck preventive maintenance program

Each step turns one part of Part 396 into a routine with an owner.

Step 1: List every unit, trailers included

The annual inspection applies to each vehicle in a combination: tractor, semitrailer, full trailer, and converter dolly. Record each unit's company number, make, serial number, and year, and who furnished any unit you don't own.

Step 2: Set intervals and due dates

Start from the manufacturer's schedule, adjust for your miles and duty cycle, and record the due date of every task. Section 396.3(b)(2) requires exactly that.

Step 3: Close the DVIR loop

Turn every reported defect into a work order. Repair anything likely to affect safety before dispatch, certify it on the report, and have the next driver sign. Keep all of it for 3 months.

Step 4: Qualify who inspects and who works on brakes

Annual inspectors need a federal- or state-sponsored training program, a state or provincial certificate, or at least 1 year of qualifying training or experience. Brake work needs a qualified brake inspector. Keep the evidence while they work for you, and for 1 year after.

Step 5: File records where the truck is kept

Keep maintenance records where the vehicle is housed or maintained, annual inspection reports for 14 months, and proof of the last annual inspection on the vehicle. Our DOT safety compliance team helps carriers set up these vehicle files.

Step 6: Feed roadside results back into the schedule

Review inspection reports monthly, by unit. When the same tire or brake finding repeats, fix the interval or the check, not just the part. Our compliance programs include CSA monitoring and mock audits.

Technician checking the brakes on a semi-trailer axle with a flashlight in a trailer yard
Trailers need their own annual inspection. A fleet list that stops at the tractors leaves half the program out.
How Simplex Helps

How Simplex helps you run preventive maintenance

Your mechanics do the work. We help with the files, the routines, and the inspection data around it.

01

Maintenance compliance

Our DOT safety compliance team covers equipment maintenance and repair compliance, including vehicle files with the annual inspection and maintenance receipts.

02

Inspections in one view

SimplexHub shows your BASIC scores and the last 24 months of inspections and violations, linked to driver and equipment details.

03

Ready for the safety audit

Our safety audit guidance and support covers maintenance and inspections alongside hours of service and driver qualifications.

Talk to Our Team
Your Questions, Answered

Frequently asked questions

What is a PM on a truck?+
A PM is a scheduled preventive maintenance service: inspection, lubrication, fluid and filter service, adjustments, and replacing worn parts before they fail. The carrier sets the intervals, usually from the manufacturer's schedule, and must track what is due and when under 49 CFR 396.3.
What should a truck preventive maintenance checklist include?+
At minimum: the 11 items drivers report on the DVIR, lubrication and leak checks, every item on the manufacturer's service schedule, and the 15 categories of the annual inspection in Appendix A to Part 396.
How often does the DOT require a truck to be inspected?+
Every commercial motor vehicle must pass a periodic inspection at least once every 12 months, with proof on the vehicle. Drivers also check the vehicle before each trip and report defects in writing at the end of each day's work.
Do trailers need an annual DOT inspection?+
Yes. 49 CFR 396.17 applies to each vehicle in a combination, so the tractor, each semitrailer or full trailer, and any converter dolly must each be inspected.
How long must truck maintenance records be kept?+
Maintenance records: 1 year where the vehicle is housed or maintained, and 6 months after it leaves your control. Annual inspection reports: 14 months. DVIRs and repair certifications: 3 months.
Can a DVIR be electronic?+
Yes. Since March 23, 2026, 49 CFR 396.11 and 396.13 state explicitly that the reports may be created and kept in electronic format under 49 CFR 390.32.
Sources & Author

Where this information comes from

The requirements below come from federal regulations, FMCSA's Safety Measurement System documents, CVSA, and ATRI, checked on September 24, 2026.

Inely Baez, Chief Operating Officer of Simplex Group

Written by

Inely Baez

Chief Operating Officer, Simplex Group

Chief Operating Officer at Simplex Group, with nearly eight years at the company leading operational strategy and execution across compliance, technology, logistics, and performance systems. She is a Certified Public Accountant with a background spanning operations and finance, including leadership roles within Simplex's Freight 4 U division and Velox Transport Solutions. Her work focuses on building scalable, disciplined systems that support long-term performance and growth.

Published · Updated

Before the Next PM

Make maintenance a schedule you can prove

Mechanics fix trucks. Your program decides whether the right work happens on time, and whether your records show it at a roadside inspection or an audit.

If you want help setting up vehicle files, DVIR routines, and a monthly inspection review, talk to our team.

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