A trailer inspection checklist is a walk from the fifth wheel to the rear doors, checking the coupling, air and electrical connections, landing gear and frame, wheels and brakes, doors and lights, and the load. Trailers are easy to skip because the tractor gets the attention, yet tires, brakes, lights and cargo securement are the categories that put the most vehicles out of service. This page has 24 checks in six stations, and every one says what failure looks like. Schedule a call to put your trailer checks on every driver's phone, or compare it with the tractor pre-trip checklist.
TRAILER INSPECTIONS · DRIVERS, YARD CREWS AND FLEET MANAGERS
Check the Connection Before You Check Anything Else
A trailer that is not fully coupled is the one defect that cannot be fixed on the road. Start at the fifth wheel, finish at the rear doors, and write down what you find.
WHAT A GOOD COUPLING LOOKS LIKE
No gap between the plates. If you can see daylight, do not move.
Where Trailers Lose Inspections
At the 2025 International Roadcheck, inspectors wrote 13,553 out-of-service vehicle violations across 56,178 inspections. Four of the five biggest categories are trailer items, and they set the order of the stations below.
VEHICLE OUT-OF-SERVICE VIOLATIONS BY CATEGORY, 2025 ROADCHECK
3,304
2,899
2,257
1,737
1,549
1,807
Brake systems
Tires
Brakes out of adjustment
Lights
Cargo securement
All other
Counts cover all commercial vehicles in the event, not trailers alone. "All other" is the remainder after the five published categories.
The Checklist: Six Stations, Front to Back
Each check has a plain description of what failing looks like, so a driver does not have to guess whether something counts. Tick a box only after you have looked.
1
Coupling and kingpin
- Kingpin fully seated in the fifth wheel jawsFail: There is a visible gap between the plates or the jaws are not locked.
- Release handle latched and locking pin in placeFail: The handle is not fully home.
- Fifth wheel mounting bolts present and tightFail: Bolts are missing or the mount is cracked.
- Tug test: pull gently against the trailer brakesFail: The trailer moves or the connection shifts.
2
Air lines and electrical
- Glad hands seated, seals intact, no audible leaksFail: Air leaks you can hear, or lines are chafed through.
- Air lines and electrical cable routed clear of tiresFail: Lines drag, kink or are cut.
- Air holds steady with the engine offFail: Pressure drops faster than the test allows.
- ABS lamp goes out after the trailer is powered upFail: The lamp stays on.
3
Landing gear, frame and suspension
- Landing gear fully raised and crank securedFail: Gear is bent, loose or not fully raised.
- Frame rails and crossmembers free of cracksFail: A crack or break is visible.
- Sliding tandem pins fully engagedFail: A pin is missing or not engaged.
- Springs, hangers and air bags intactFail: A broken spring or deflated air bag.
4
Wheels, tires and brakes
- Tread at least 2/32 in on every trailer tireFail: Tread is below the limit, or cords show.
- Tires inflated correctly, no bulges or cutsFail: A flat, bulge or sidewall cut.
- All lug nuts present, hub seals dryFail: A missing lug nut or oil on the wheel.
- Brake chambers, pushrods and slack adjusters soundFail: Stroke over the limit or a leaking chamber.
5
Doors, rear and lights
- Doors close, latch and sealFail: A door that will not latch.
- Rear impact guard straight and uncrackedFail: Guard is missing, bent or cracked.
- Tail, brake, turn, marker and clearance lights workFail: Any required lamp is out.
- Red and white reflective tape complete and visibleFail: Large sections are missing. Faded tape is a defect to report.
6
Load and paperwork
- Cargo blocked, braced and tied downFail: Cargo can shift, or tiedowns are damaged.
- Tiedown rating covers the loadFail: Total working load limit is under 50% of cargo weight.
- Seal number matches the paperworkFail: Seal is missing or does not match.
- Registration, annual inspection and DVIR book on handFail: A required document is missing.
Want the fail wording on every driver's screen?
Tell us how many trailers you pool and we will set up a check that flags the shop when a driver marks a fail.
Add These Checks for Your Trailer Type
The six stations apply to every trailer. Add the block that matches the equipment.
DRY VAN
Floor free of holes and soft spots
Door seals and gaskets intact
Logistic tracks and load bars secure
Roof free of leaks
REEFER
Unit fuel, oil and belts checked
Setpoint matches the load
Door seals and bulkhead intact
Drain lines clear
FLATBED
Straps free of cuts and rated
Chains, binders and winches sound
Edge protectors and dunnage on hand
Tarps and bows undamaged
TANKER
Valves and manway lids sealed
No product leaks at fittings
Vents and gauges working
Placards correct and legible
Tiedown Math for Flatbeds and Open Loads
Federal cargo securement rules are in 49 CFR Part 393. Two numbers cover most loads: how much total strength the tiedowns need, and how many of them. Read the general rule.
1
Weigh the cargo
Example: 20,000 lb.
→
2
Halve it
Total working load limit must be at least 50% of the weight, so 10,000 lb.
→
3
Count tiedowns
Use the length rules in the table, then check each strap's rating.
← Swipe to see all columns →
| Cargo length | Cargo weight | Minimum tiedowns |
|---|---|---|
| Up to 5 ft | Up to 1,100 lb | 1 |
| Up to 5 ft | Over 1,100 lb | 2 |
| Over 5 ft, up to 10 ft | Any | 2 |
| Over 10 ft | Any | 2, plus 1 for each additional 10 ft or fraction |
Replace the Trailer Clipboard With a Walkaround That Is Always Filled In
FleetRabbit's DVIR app puts the six stations on the driver's phone, asks for a photo on any failed check, and sends defects to the shop as work orders. Electronic reports are stored with a timestamp, so there is nothing to lose between the yard and the road. Read the federal report rule.
Six-station walkaround
Fail wording built in
Photo on every defect
Reports stored and searchable
Frequently Asked Questions
What should a trailer inspection checklist include?
The coupling and kingpin, air lines and electrical connection, landing gear, frame and suspension, wheels, tires and brakes, doors, rear guard and lights, and the load and paperwork. This page groups them into six stations.
What is the minimum tire tread for a trailer?
Federal rules set 2/32 of an inch on trailer tires, and 4/32 on steering tires. Some fleets replace trailer tires earlier.
Does a trailer need its own DVIR?
The driver's report covers every vehicle in the combination, including the trailer, and any defects found must be reported in writing. Read 49 CFR 396.11.
Can the DVIR be done electronically?
Yes. Federal rules allow electronic driver vehicle inspection reports, and a 2026 FMCSA rule made that explicit. Keep the same fields and the same retention as paper.
What is the tug test?
After coupling, the driver sets the trailer brakes and gently pulls the tractor forward. If the trailer holds and the connection does not shift, the fifth wheel is locked on the kingpin.
Is a trailer inspection PDF enough?
A PDF is a good template, but paper is easy to lose and cannot alert the shop. A digital form keeps every report and turns failures into work orders. Schedule a call to see how it works.
What does FleetRabbit cost for trailers?
FleetRabbit is free for up to three vehicles and $5 per vehicle per month after that. Inspect your first trailer free.
Front to Back, Every Time
A driver who walks the same six stations on every trailer catches the loose coupling, the dead light and the worn tire before they become a roadside stop. Give them the route and give your shop the reports.
Free tier for up to 3 vehicles · No credit card required · Reports stored with timestamps
October 9, 2026By Derek Goes
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