Preventive maintenance schedule for semi trucks

What preventive maintenance means for a truck fleet

Preventive maintenance (PM) is planned work done before something fails: scheduled inspections, oil and filter changes, lubrication, adjustments and replacing parts that have reached their wear limit. Reactive repair is the opposite: the truck breaks, then the shop finds out.

Canada’s maintenance standard puts the goal plainly: regular preventive maintenance lets small problems be corrected before they result in accidents, major repairs or a breakdown. For a carrier that also means fewer roadside out-of-service orders, fewer missed appointments and trucks that last longer.

A PM program has three working parts:

• The schedule: which services each unit gets, and when they come due by miles, days or engine hours.
• The checklist: what the technician inspects, measures, changes and greases at each service level.
• The record: the date, odometer and work done at every visit, kept for each vehicle.

Driver inspections feed the program. Defects that drivers write up on a DVIR or trip inspection report should be cleared at the next shop visit, and the PM checklist should start by looking at them.

What the rules require in the US and Canada

United States: 49 CFR 396.3

Every motor carrier must systematically inspect, repair and maintain, or cause to be systematically inspected, repaired and maintained, all motor vehicles subject to its control. Parts and accessories must be in safe and proper operating condition at all times, including the frame, suspension, axles, wheels and rims, and steering.

The rule also requires a record for each vehicle the carrier has controlled for 30 consecutive days, showing:

• the vehicle’s identification: company unit number if marked, make, serial number and year, and the name of whoever furnished it if the carrier does not own it;
• a means to indicate the nature and due date of the various inspection and maintenance operations to be performed;
• a record of inspections, repairs and maintenance, with their date and nature.

That second item is the PM schedule itself: the regulation expects you to be able to show what is due on each truck and when. Records are kept where the vehicle is housed or maintained: 1 year, and 6 months after the vehicle leaves your control. The separate annual periodic inspection is covered in our DOT annual inspection guide.

Canada: NSC Standard 11, Part A

National Safety Code Standard 11 is the national maintenance standard, and the provinces adopt it by reference or mirror it in their own laws. Every operator must have a system to inspect, maintain and repair each owned or leased vehicle, trailers included, at regular intervals. The standard sets no fixed intervals, leaving them to the carrier, although it notes that some jurisdictions set a maximum distance or time between services.

The vehicle file should hold, at a minimum: make, model, year and VIN; the lessor’s name if leased; the date and nature of every repair and maintenance job, with parts and invoices; the odometer reading at every service or repair; a description of the type and frequency of regular maintenance; and a record of any axle or suspension change that affects the vehicle’s rated gross or axle weight.

Records are kept for at least two years at your principal place of business and may be discarded six months after a vehicle is sold, destroyed or returned to its lessor. The standard adds that many jurisdictions want proof of maintenance, such as brake repair invoices, kept for four or five years, so check your province. Compliance is checked in facility audits: the auditor picks vehicles at random and asks for their files.

Ontario, for example, says preventive maintenance inspections must be part of an operator’s maintenance plan and schedule and be done by a qualified technician at prescribed intervals.

A, B and C service levels

Most fleets do not run one PM. They run a cycle of service levels that differ in depth, and NSC Standard 11 describes the common pattern. The intervals below are the examples the standard gives, not legal limits; yours should come from your manuals and your operation.

Two points from the standard are worth taking straight into your shop. First, whatever schedule you pick, by time or by distance, you must actually follow it; an auditor compares the plan with the record. Second, if your technicians measure brake components and keep the repair invoices during normal PM, you may avoid pulling wheels at the periodic inspection, because Part B of the standard allows alternative methods for internal brake components when earlier inspections are properly documented.

Setting intervals: miles, time or engine hours

Standard 11 calls the original equipment maker’s service schedule the single best piece of advice for designing a maintenance program. Engine, transmission, axle and trailer component makers publish intervals, and many publish more than one schedule depending on how hard the equipment works. Pick the schedule that matches your duty cycle, not the most generous one.

Each interval needs a trigger. The three common ones suit different equipment:

• Miles or kilometres: the natural trigger for highway tractors, where wear tracks distance. Take readings from the odometer or the ELD rather than from dispatch estimates.
• Time: suits units that sit, trailers without a reliable odometer, and items that age whether or not the unit moves, such as fluids and the periodic inspection date.
• Engine hours: common for trucks that idle a lot or drive equipment while parked, where the engine works without adding miles.

Many fleets combine triggers and service at whichever comes first, for example a distance or a number of days. That protects low-mileage units from going a year between services while keeping high-mileage units on a distance cycle.

Then adjust with evidence. If roadside inspections keep finding brakes out of adjustment, or a model keeps losing the same part between services, shorten that interval or add the item to the A service. If B services keep finding nothing, the manual and your records may support a longer interval. Change one thing at a time and write down why.

Worked example

Unit 114 is a highway tractor on a B service every 25,000 km or 90 days, whichever comes first, which sits inside the range Standard 11 gives as an example. Its last B service was on March 3 at 412,000 km, so the next one is due at 437,000 km or on June 1. The truck runs about 2,400 km a week, so it reaches 437,000 km around May 15, about two weeks before the date. Distance comes first, and the shop books it for the week of May 11. The same arithmetic works in miles.

Sample PM checklist for a semi truck

Use this as a starting point and add every item your engine and component manuals call for. The systems follow the groups in NSC Standard 11 and in the US periodic inspection standard, so a unit that passes its C service should be ready for its periodic inspection.

How to build your PM schedule, step by step

1. List every unit. Unit number, VIN, make, model and year, owner or lessor, current odometer and, where it matters, engine hours. This is also the identification record both countries require.
2. Collect the makers’ schedules. Engine, transmission, axles, aftertreatment and trailer components. Note which schedule fits your duty cycle.
3. Group the work into levels. Put each item into A, B or C so every visit has a fixed checklist and a predictable shop time.
4. Choose the trigger for each level. Distance, days, hours or whichever comes first. Trailers usually run on days.
5. Add the periodic inspection date for every truck, trailer and dolly, and line up the C service before it.
6. Write the program down. US rules ask for the nature and due date of each operation, and Canadian auditors look for the type and frequency of regular maintenance.
7. Close the loop with drivers. Every defect on an inspection report gets repaired or marked as not needing repair before the next trip, and the PM visit checks that it was.
8. Review monthly. Compare breakdowns, roadside inspection results and repeat repairs with the schedule, and adjust intervals with a written reason.

Keep each vehicle’s history in one place. A complete file answers an auditor’s question in minutes, and it is the evidence you need to extend or shorten an interval. If you also manage DOT driver files and other safety records, TruckerPro’s DOT compliance tools sit in the same TMS that RigMD runs on.