A PM service checklist tells a technician exactly what to inspect at each service tier, and a tiered system keeps cheap, frequent checks separate from the longer annual service. This page lists the items for Class A, B, C and D heavy-duty PM services, with tick boxes, typical intervals and labor time for each tier. Schedule a call to load these checklists into your PM schedule.
PM CHECKLIST · SHOP LEADS AND FLEET MANAGERS
Four Service Tiers, 46 Tick-Box Items: What Gets Inspected at Every PM Visit
Work down the list for the tier that is due. Each tier builds on the one before it, so nothing falls between visits.
LABOR TIME BY TIER
Class A1 to 2 hours
Class B2 to 3 hours
Class C4 to 6 hours
Class D is planned by condition.
How the Class A, B, C and D PM Tiers Work
Each class adds to the one before it, so a Class C visit covers A and B as well
Class A is the short, frequent safety service. Class B adds measured intermediate checks. Class C is the comprehensive annual service that includes the DOT inspection. Class D is a major overhaul planned by condition. Intervals vary by source and by engine maker, so treat the ranges below as starting points and use your OEM manual for the final numbers.
1
Class A
Every visit: the base 12 items
→
2
Class B
A plus 12 intermediate items
→
3
Class C
A and B plus 12 annual items
→
4
Class D
Overhaul, planned by condition
Typical intervals overlap, and the sources do not agree exactly
One checklist guide gives Class A at 5,000 to 15,000 miles and Class B at 10,000 to 30,000. Another gives narrower ranges of 5,000 to 10,000 and 10,000 to 20,000 miles. The chart uses the wider ranges, and the right number for your trucks depends on duty cycle, engine and OEM guidance.
TYPICAL SERVICE INTERVAL BY TIER, MILES. HEAVY VEHICLE INSPECTION (HVI) GUIDE; CLASS C ALSO ANNUAL
Class A
5,000 - 15,000 mi
Class B
10,000 - 30,000 mi
Class C
25,000 - 60,000 mi or yearly
Class D
100,000+ mi or as needed
0k
30k
60k
90k
120k
Class A PM Checklist: The Basic Safety Service
Twelve items, done most often, that keep the truck safe and legal between longer services
A
Class A: Basic Safety Service
Interval: about every 5,000 to 15,000 miles or 250 to 500 engine hours · Labor: about 1 to 2 hours
Engine oil and filter change
Fluid levels topped off
Air filter condition
Tire pressure, tread and condition
Visual brake check
Lights and reflectors
Belts and hoses (visual)
Wipers and washer fluid
Battery and connections
Chassis lubrication
Check for leaks
Road test
Want the Class A list on every truck's schedule? Schedule a call and we will set it up.
Tick boxes become a checklist the technician completes on a phone or tablet.
Class B PM Checklist: The Intermediate Service
Twelve more items that measure wear instead of just looking for it
B
Class B: Intermediate Service (includes every Class A item)
Interval: about every 10,000 to 30,000 miles or 500 to 1,000 engine hours · Labor: about 2 to 3 hours total
Fuel filters replaced
Air filter replaced if needed
Brake lining thickness measured
Slack adjusters checked
Steering components
Suspension components
Battery load test
Alternator output
Exhaust system
U-joints and driveshaft
Wheel seals and bearings
ECM fault code review
Add these 12 items to the Class A list.
Class C PM Checklist: The Comprehensive Annual Service
Fluids, alignment, diagnostics and the DOT annual inspection in one visit
C
Class C: Comprehensive Service (includes Class A and B)
Interval: about every 25,000 to 60,000 miles, or yearly · Labor: about 4 to 6 hours total
Transmission fluid service
Differential fluid service
Coolant service
Power steering fluid service
Wheel alignment
DOT annual inspection
Air system inspection
Fifth wheel inspection
Frame and crossmember
Oil and coolant sampling
Full diagnostic scan
Wear parts replaced as found
Add these 12 items to the Class A and B lists. Schedule it at 11 months so the DOT annual inspection never lapses.
Class D: Major Overhaul and Special Service
Plan it from condition and diagnostics, because no fixed interval fits every truck
D
Class D: Major Overhaul and Special Service
Interval: about 100,000 miles and up, or as condition requires · Labor: not specified in sources
Engine overhaul or replacement
Transmission overhaul or replacement
Axle and differential overhaul
Brake system rebuild
Suspension and steering rebuild
Fuel system reconditioning
Cooling system replacement
Electrical and technology upgrades
Winterization or summerization
Resale preparation
Class D has no fixed interval. Plan it from condition, diagnostics and OEM guidance.
How Long Each PM Class Takes in the Bay
Plan labor hours per tier, and add a buffer for repairs found during the inspection
The estimates below are labor time and not downtime. A truck waiting on parts or a bay stays out of service longer than the labor hours suggest. No time is given for Class D because the scope varies too much.
ESTIMATED LABOR HOURS BY TIER. HVI GUIDE; ESTIMATES, NOT DOWNTIME
Class A
1 - 2 hours
Class B
2 - 3 hours total
Class C
4 - 6 hours total
0h
1h
2h
3h
4h
5h
6h
Group Class A with a tire or lube stop
Short visits fit around a route, so book them where the truck is already parked.
Block a half day for Class C
Four to six labor hours plus the inspection means it rarely fits into a gap.
Schedule Class C at 11 months
This keeps the DOT annual inspection from lapsing while the truck is in the bay.
Adjust the Checklists for Your Fleet
Shorten intervals for hard duty, and change the items to match the equipment
Shorten the interval when
Trucks idle for long periods, so use engine hours
Work is dusty, stop-and-go or off-road
Loads run at or near the weight limit
Cold or hot climates are the norm
Customize the items when
The engine maker lists different checks
You run reefers, tankers or dump bodies
Trailers need their own schedule
Past repairs show a repeat failure
Run Class A, B, C and D PM Checklists Automatically: Schedule Services by Miles or Hours in FleetRabbit
FleetRabbit lets you build a checklist for each PM tier, assign it to each truck and trigger it by miles, engine hours or calendar date. Technicians tick items off on a phone, and every completed service stays on the vehicle's record.
A, B, C and D templates
Triggers by miles, hours or date
Reminders before due
Service history per truck
Frequently Asked Questions
Quick answers on Class A, B, C and D PM services
What is the difference between Class A, B, C and D PM services?
Class A is a basic safety service, Class B adds intermediate measured checks, Class C is the comprehensive annual service with the DOT inspection, and Class D is a major overhaul planned by condition.
How often should each PM class be done?
Typical ranges are 5,000 to 15,000 miles for A, 10,000 to 30,000 for B, 25,000 to 60,000 or yearly for C, and 100,000 miles or more for D. Check your engine maker's manual for exact numbers.
How long does each service take?
Roughly 1 to 2 hours for A, 2 to 3 for B and 4 to 6 for C, as labor estimates. Class D varies too much to estimate.
Does a Class C service include the earlier tiers?
Yes. Each class includes the items from the lower classes, so a Class C visit covers A, B and the annual items.
When should the DOT annual inspection be done?
It runs on its own 12-month clock. Scheduling the Class C service at 11 months leaves a buffer so it never lapses.
Should I use miles, engine hours or dates?
Use miles for steady highway units, engine hours for idle-heavy trucks and the calendar for low-use units. Many fleets set a mileage and a date and service at whichever comes first.
What does FleetRabbit cost?
FleetRabbit is free for up to three vehicles and $5 per vehicle per month after that. Track 3 vehicles free.
Turn the Four PM Tiers Into Checklists Your Technicians Complete on Every Truck
A tiered checklist only works when each service is scheduled, completed and recorded. Load the lists once, let reminders trigger them, and keep every tick box on the truck's record.
Free tier for up to 3 vehicles · No credit card required · Checklists stored per unit
October 12, 2026By Emily Parker
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