WHEN SHOULD YOU HAVE YOUR TRAILER PROFESSIONALLY INSPECTED?
Know which trailer problems require more than a quick visual check.
Serving Trailer Buyers Since 2007 | Douglas, Georgia | Custom Trailers Available
Routine owner inspections are an important part of trailer safety, but some problems require professional equipment, training and experience to diagnose correctly.
Brake problems, excessive hub heat, uneven tire wear, wheel movement, damaged suspension components and structural cracks can affect how a trailer tracks, stops and handles on the highway.
Knowing when to stop towing and arrange a professional inspection can help prevent a minor problem from becoming a roadside failure or more extensive repair.
Quick Answer: When Should a Trailer Be Professionally Inspected?
Have your trailer professionally inspected when you notice:
- Weak, uneven, noisy or unpredictable braking
- One wheel or hub becoming unusually hot
- Wheel looseness, wobbling or abnormal movement
- Rapid or uneven tire wear
- A trailer that pulls, wanders or tracks incorrectly
- Bent, broken or loose suspension components
- Persistent lighting or electrical problems
- A breakaway system that does not operate correctly
- Cracked welds or visible frame damage
- Damage following an accident, curb strike or severe pothole
- Any safety-related problem you cannot confidently identify
Important
If the trailer has a wheel wobble, significant brake failure, smoke, a burning smell, a severely overheated hub, broken suspension component, damaged tire or cracked frame, stop towing as soon as it is safe.
Owner Inspection vs. Professional Inspection
A pre-trip inspection does not replace a professional mechanical inspection.
Owner Pre-Trip Inspection
An owner can normally check:
- Tire pressure
- Visible tire damage
- Trailer lights
- Electrical plug condition
- Safety-chain connection
- Coupler connection
- Breakaway cable connection
- Door and ramp security
- Visible cargo securement
- Obvious leaks or damage
Professional Trailer Inspection
A qualified technician may need to inspect:
- Internal brake components
- Brake adjustment and operation
- Wheel bearings and bearing adjustment
- Hubs and brake drums
- Grease seals
- Wheel studs and lug-nut seating
- Axle alignment
- Springs, shackles and equalizers
- Torsion-axle mounting points
- Frame and tongue alignment
- Welds and structural connections
- Electrical voltage and ground circuits
- Breakaway battery and switch operation
Pro Tip
A trailer can look normal while still having worn brake components, contaminated brake linings, loose bearings, damaged wiring or suspension wear underneath it.
1. Abnormal Trailer Braking
Trailer brakes should operate smoothly and predictably.
Arrange a professional brake inspection if the trailer:
- Pushes the tow vehicle during braking
- Pulls toward one side
- Grabs or locks unexpectedly
- Surges during braking
- Makes scraping, grinding or unusual noises
- Requires substantially more brake-controller gain than before
- Produces a burning smell
- Has brakes that remain applied after the pedal is released
- Has noticeably reduced stopping performance
Brake-controller adjustments cannot correct every brake problem. Weak braking may be caused by worn components, poor adjustment, damaged magnets, contaminated linings, wiring problems or an issue inside the hub and drum assembly.
Safety Callout
A sudden change in braking performance is a warning sign. Do not continue increasing the brake-controller gain without determining why the trailer’s braking has changed.
2. A Hot Wheel or Hub
Some heat is expected during normal towing and braking, but one hub that is substantially hotter than the others can indicate a problem.
Possible causes include:
- A dragging brake
- Improper bearing adjustment
- Insufficient or contaminated lubricant
- A damaged bearing
- A failing grease seal
- Brake components that are not releasing
- Excessive or uneven braking
Warning signs may include:
- Heat coming from one wheel
- A hot-metal or burning odor
- Smoke near the hub
- Grease leaking around the wheel
- Discoloration around the hub
- Grinding or humming sounds
Do not touch a suspected overheated hub with your bare hand. It may be hot enough to cause an injury.
Stop-Towing Warning
A smoking, severely overheated or noisy hub should be inspected before the trailer is moved again. A bearing or hub failure can allow the wheel to lock up, loosen or separate from the trailer.
3. Uneven or Rapid Tire Wear
Tires provide important clues about the condition of a trailer’s running gear.
Professional inspection may be needed when you see:
- Heavy wear on one edge of a tire
- One tire wearing faster than the others
- Cupping or scalloped tread
- Repeated tire damage in the same position
- Visible rubbing against the trailer
- A tire leaning inward or outward
- Recurring pressure loss
- Sidewall bulges or exposed cords
Uneven wear may be related to:
- Improper tire pressure
- Overloading
- Bent or damaged wheels
- Axle alignment
- Suspension wear
- Incorrect wheel offset
- Damaged axle components
- Uneven cargo distribution
Replacing the tire without correcting the underlying problem may result in the new tire wearing the same way.
4. Wheel Movement or Loose Components
A trailer wheel should rotate smoothly without abnormal side-to-side movement.
Warning signs include:
- Visible wheel wobble
- Clicking or grinding while the wheel turns
- Loose or damaged wheel studs
- Lug nuts that repeatedly loosen
- Cracked or distorted wheels
- Grease leaking from the hub
- Wheel movement that can be felt during inspection
Wheel looseness may involve the bearings, hub, spindle, wheel, studs or lug nuts. These are safety-critical components and should be inspected before further towing.
Important
Never crawl underneath a trailer or remove wheels unless it is supported correctly with equipment rated for the trailer’s weight. Never rely on the tongue jack or an unsuitable jack to support a trailer.
5. The Trailer Pulls or Tracks Incorrectly
A properly loaded trailer should follow the tow vehicle without consistently pulling or traveling at an angle.
Schedule an inspection if the trailer:
- Appears to travel sideways or “dog-track”
- Pulls consistently toward one side
- Wanders despite correct loading
- Leans noticeably
- Sits unevenly on level ground
- Develops repeated tire wear
- Feels unstable after tire pressure and cargo position are corrected
Tracking problems can be caused by:
- Axle misalignment
- A bent axle
- Broken or worn suspension components
- Uneven ride height
- Frame or tongue damage
- Improper wheel or tire fitment
- Severe cargo imbalance
Loading problems should be corrected first, but a trailer that continues tracking incorrectly needs a professional inspection.
6. Suspension or Axle Damage
Leaf-spring and torsion-axle systems should be inspected according to the component manufacturer’s instructions.
Professional attention is needed when you find:
- A broken spring leaf
- A spring that has lost its normal shape
- Damaged shackles
- Worn equalizers or bushings
- Loose or damaged hangers
- Loose or shifted U-bolts
- Bent suspension components
- Cracks around suspension mounting points
- A torsion axle sitting unevenly
- One side of the trailer riding lower than the other
- Unusual clunking or metal-on-metal noises
Suspension damage can change wheel alignment and increase stress on the remaining components.
Do not continue towing with a broken spring, loose suspension mounting point or visibly damaged axle.
7. Persistent Electrical Problems
A burned-out bulb may be simple to replace. Repeated or intermittent electrical problems may require professional diagnosis.
Arrange an electrical inspection if:
- Trailer lights work intermittently
- Multiple lights fail at the same time
- Fuses repeatedly blow
- The trailer plug becomes unusually hot
- Wiring insulation is cut, melted or damaged
- Lights change when the trailer moves
- The brakes work intermittently
- The tow vehicle does not consistently recognize the trailer
- The breakaway battery does not hold a charge
- The breakaway switch does not operate correctly
Electrical problems may result from:
- A weak or missing ground
- Corroded connections
- Damaged wiring
- Pinched wires
- Incorrect previous repairs
- A damaged trailer plug
- Brake-magnet wiring problems
- Battery or charging-system failure
Pro Tip
Do not replace the same fuse repeatedly without finding the cause. A fuse that continues blowing usually indicates an unresolved electrical problem.
8. Hitch, Coupler or Safety-Chain Damage
The trailer tongue and connection system transfer towing and braking forces between the trailer and tow vehicle.
Have the trailer inspected if you notice:
- A coupler that will not close or lock correctly
- Excessive coupler movement
- A bent tongue
- A damaged tongue jack
- Cracks around the coupler
- Loose or missing coupler fasteners
- Damaged safety-chain mounts
- Cracked or stretched safety chains
- A breakaway-switch mount that is loose or damaged
- Visible movement where the tongue connects to the frame
Do not weld, drill or modify the tongue, coupler or safety-chain attachment points without confirming that the repair or modification is appropriate for the trailer.
9. Cracked Welds or Structural Damage
The trailer frame, tongue and suspension mounting points carry significant loads.
Inspect visible welds regularly, especially around:
- The tongue
- Coupler mounting area
- Spring hangers
- Axle mounting points
- Rear crossmembers
- Ramp-door frame
- Jack mounting points
- Stabilizer mounting points
- Cargo tie-down attachments
Warning signs include:
- Hairline cracks
- Rust lines emerging from a weld
- Flaking paint around a connection
- Separation between joined components
- Bent frame members
- Buckled flooring above the frame
- Doors that suddenly become difficult to align
- A trailer body that appears twisted or uneven
A cracked weld should be evaluated before it grows into a larger structural problem.
Inspection After an Accident or Impact
A trailer should be professionally inspected after:
- A collision
- A wheel striking a curb
- A severe pothole impact
- A tire blowout that damaged the trailer
- The trailer leaving the roadway
- A load shifting violently
- A coupler or hitch separation
- A jackknife incident
- Suspected overloading
- Contact with an overhead obstruction
Damage may extend beyond the area that was struck. An impact can affect axle alignment, suspension mounting points, wheels, tires, wiring, brakes, the tongue or the main frame.
Do not assume the trailer is safe because the exterior damage appears minor.
Inspection After Long-Term Storage
Before returning a stored trailer to regular use, inspect:
- Tires and valve stems
- Wheels and lug nuts
- Hubs and bearings
- Brake operation
- Breakaway system
- Battery condition
- Trailer lights
- Electrical connector
- Suspension components
- Coupler and safety chains
- Frame and visible welds
- Doors, ramps and latches
A professional inspection is especially important when the trailer:
- Has been stored for an extended period
- Was parked outdoors without regular checks
- Has evidence of water intrusion
- Has corroded components
- Has a dead or damaged battery
- Has not received maintenance according to its manufacturer’s schedule
- Will be used for a long or heavily loaded trip
How Often Should a Trailer Be Professionally Inspected?
There is no single inspection schedule that fits every trailer.
Inspection frequency depends on:
- Trailer manufacturer recommendations
- Axle and brake manufacturer requirements
- Annual mileage
- Load weight
- Road conditions
- Storage conditions
- Commercial or personal use
- Frequency of use
- Trailer age
- Previous repairs
- Exposure to moisture, road salt or coastal conditions
A trailer used daily for commercial hauling may require more frequent attention than one used occasionally for light cargo.
Always follow the maintenance schedule provided by the trailer, axle, brake, tire and accessory manufacturers.
Important
Do not wait for the next scheduled service if the trailer develops a safety-related symptom. Performance changes, heat, noise, looseness or visible damage should be investigated promptly.
What Should a Professional Trailer Inspection Include?
The exact inspection should be based on the trailer’s design, equipment and reported symptoms.
A comprehensive inspection may include:
Tires and Wheels
- Tire condition and age
- Pressure requirements
- Uneven wear
- Wheel condition
- Lug nuts
- Wheel studs
- Correct wheel and tire specifications
Hubs and Bearings
- Bearing condition
- Bearing adjustment
- Lubricant condition
- Grease seals
- Hub and drum wear
- Evidence of overheating
Brakes
- Brake adjustment
- Shoes or pads
- Magnets
- Springs and hardware
- Drums or rotors
- Wiring and voltage
- Brake-controller response
- Breakaway operation
Axles and Suspension
- Axle condition
- Alignment
- Springs
- Shackles
- Equalizers
- Bushings
- Hangers
- U-bolts
- Torsion-axle mounting points
Frame and Tongue
- Main-frame condition
- Crossmembers
- Tongue alignment
- Coupler mounting
- Safety-chain mounts
- Welds
- Jack mounting points
- Evidence of corrosion or impact damage
Electrical System
- Trailer plug
- Wiring
- Ground connections
- Exterior lighting
- Brake wiring
- Battery
- Breakaway switch
- Charging circuit
What to Tell the Trailer Technician
Give the technician as much information as possible.
Explain:
- When the problem started
- Whether it happens loaded or empty
- Whether it occurs during braking
- Which side of the trailer seems affected
- Whether you noticed heat, noise or vibration
- Whether the trailer recently struck a curb or pothole
- Whether a tire or component was recently replaced
- Whether the trailer has been overloaded
- What repairs have already been attempted
- The trailer’s axle and brake type when known
Photos, videos and notes may help when a problem happens intermittently.
Bring the trailer’s VIN, axle information and service records when available.
Do Not Ignore These Warning Signs
Arrange an inspection when you notice:
- Changed braking performance
- Burning odor or smoke
- Abnormally hot wheel or hub
- Grease leaking around a wheel
- Grinding, scraping or clunking noises
- Wheel wobble or looseness
- Rapid or uneven tire wear
- Trailer pulling or tracking sideways
- Broken or bent suspension components
- Repeated electrical failures
- Breakaway-system problems
- Damaged coupler or safety chains
- Cracked welds
- Bent tongue or frame
- Damage following an accident or impact
Frequently Asked Questions
Can I Tow a Trailer With a Hot Hub?
A hub that is unusually hot compared with the others may indicate a dragging brake, bearing problem or insufficient lubrication. If the hub is severely hot, smoking, leaking grease or making noise, stop towing and have it inspected.
Can the Brake Controller Fix Weak Trailer Brakes?
The brake controller can adjust the amount and timing of braking force, but it cannot repair worn, contaminated, damaged or incorrectly adjusted brake components. A significant change in braking performance should be inspected.
What Causes Uneven Trailer-Tire Wear?
Possible causes include incorrect pressure, overloading, cargo imbalance, axle misalignment, suspension wear, damaged wheels or incorrect wheel specifications. The wear pattern should be evaluated before another tire is damaged.
Should a Trailer Be Inspected After Hitting a Curb?
A hard curb impact can damage a tire, wheel, hub, axle or suspension component. Have the affected area inspected if you notice damage, vibration, pulling, wheel movement or changed tire wear.
Is a Pre-Trip Check the Same as a Professional Inspection?
No. A pre-trip check identifies visible problems before towing. A professional inspection may involve removing wheels or hubs, measuring alignment, testing electrical circuits and examining internal brake and bearing components.
Should I Inspect a Trailer After Long-Term Storage?
Yes. Complete a thorough pre-trip inspection before towing. Arrange a professional inspection when maintenance is overdue or you find corrosion, leaks, tire damage, electrical problems, abnormal wheel movement or questionable brake performance.
Can I Repair Trailer Brakes or Bearings Myself?
Brake and bearing service requires correct tools, support equipment, specifications and procedures. If you are not properly trained and equipped, have the work performed by a qualified trailer technician.
What Information Should I Bring to a Trailer Inspection?
Bring the trailer VIN, axle identification, service history and any notes, photos or videos showing the problem. Explain when the condition occurs and whether the trailer is loaded or empty.
Related Trailer Guides
A Safer Trailer Starts With the Right Equipment
Professional inspections and routine maintenance are important throughout the life of an enclosed trailer.
Starting with a trailer that has the correct size, axle capacity, brakes, tires and construction for the job can help reduce unnecessary wear and improve towing performance.
Southern Trailer Depot offers enclosed cargo trailers, motorcycle trailers, race trailers, contractor trailers, concession trailers and custom builds.
Our team can help you compare:
- Trailer sizes
- Axle capacities
- Brake configurations
- Interior heights
- Door arrangements
- Cargo-control systems
- Finished interiors
- Electrical packages
- Custom trailer upgrades
Serving Trailer Buyers Since 2007
Located in Douglas, Georgia
Call Southern Trailer Depot: 1-888-403-1902
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