8 Signs Your Trailer Tyres May Need Replacing

By Halco Trailers Team, Trailer Manufacturing / Safety Specialist

Published: 18 September 2026

Trailer tyre replacement signs include low tread, sidewall cracking, bulges, uneven wear, repeated pressure loss, heat damage, unsuitable load rating and visible tyre or rim damage. Finding these issues early can help prevent a blowout, damaged trailer and an unexpected roadside breakdown.

Trailer tyres work differently from the tyres on a daily-driven car. They can spend long periods parked, carry heavy static loads and then suddenly face highway speeds, braking, cornering and rough worksites.

For tradies, contractors, landscapers, farmers, automotive businesses, homeowners and small business operators, checking tyres should be part of normal trailer maintenance rather than something done only after a puncture.

If you are unsure whether a tyre needs replacing, start with these eight signs.

1. The tread is worn close to the limit

Low tread is one of the clearest trailer tyre replacement signs. If the principal grooves are approaching or below the applicable legal minimum, or the tread is damaged or uneven, the tyre should be assessed before the trailer returns to the road.

Transport Victoria states that tyres must have at least 1.5 mm of tread depth in all principal grooves, except at tread-wear indicators. It also states that a tyre must not have excessive uneven wear across its width.

Transport Victoria – Tyre Maintenance and Repair

Do not treat 1.5 mm as a target you need to reach before thinking about replacement. A heavily used work trailer may need tyres replaced earlier because condition, age, cracking, heat and uneven wear also matter.

Tread condition guide

Tread condition	What it means	Recommended action
Good tread, even wear	No obvious tread-related issue	Continue regular inspections
Approaching minimum	Replacement planning should begin	Arrange tyre assessment
At or below applicable minimum	Roadworthiness issue	Replace before road use
Unevenly worn	Possible underlying fault	Inspect trailer running gear
Damaged or separated tread	Potential structural failure	Replace immediately

If you want a broader explanation of tyre replacement conditions, Halco’s trailer tyre replacement guide covers tread, cracking, pressure loss, ageing, load rating and other replacement triggers.

2. The sidewall has cracks or perishing

Sidewall cracking is a major trailer tyre wear sign because the tyre can deteriorate from age, UV exposure, storage and weather even when the tread still looks usable.

Trailer tyres are particularly vulnerable to ageing because trailers may sit outdoors for long periods. A tyre that spends months exposed to sunlight, heat and changing temperatures can deteriorate without accumulating many kilometres.

Look carefully at:

• the outer sidewall
• the inner sidewall
• areas close to the bead
• the tread shoulder
• the spare tyre
• sections hidden behind guards

Small surface marks should be monitored, but deep, spreading or structural cracks warrant replacement rather than continued loaded towing.

Signs of tyre ageing

Sign	Concern level	Action
Minor surface weathering	Monitor	Inspect regularly
Multiple sidewall cracks	High	Arrange replacement
Deep or spreading cracks	Serious	Replace before towing
Cracking around bead	Serious	Replace and inspect rim
Cracked spare tyre	Serious	Replace spare
Severe perishing across tread	Serious	Replace

A trailer that is used only occasionally should not automatically be assumed to have “good tyres” simply because the tread is deep.

3. You can see a bulge, bubble or exposed cord

A bulge, bubble or exposed cord is a serious tyre replacement sign and should not be treated as cosmetic damage. It can indicate internal structural damage caused by an impact, overload, low-pressure operation or deterioration.

Do not continue towing to see whether the bulge becomes worse.

A damaged sidewall or exposed tyre structure can fail suddenly, particularly when heat builds during highway travel. The risk becomes more significant when the trailer is heavily loaded.

Immediate replacement signs

Visible problem	Continue towing?	Why
Sidewall bulge	No	Possible internal structural damage
Bubble	No	Indicates abnormal tyre structure
Exposed cords	No	Structural material is exposed
Major sidewall cut	No	Can compromise tyre integrity
Severe tread separation	No	Potential sudden failure
Impact damage with deformation	No	Internal damage may not be visible

If a tyre has suffered a hard impact against a kerb, pothole, rock or worksite obstacle, have it inspected even if the damage appears minor.

4. The tyre is wearing unevenly

Uneven trailer tyre wear is one of the most useful warning signs because it can reveal a problem elsewhere in the trailer. The uneven wear may come from incorrect pressure, overload, axle alignment, suspension wear, bearing problems, brake drag or wheel damage.

This is why replacing a worn tyre without diagnosing the cause can be false economy.

Transport Victoria specifically identifies excessive uneven tyre wear as a tyre condition issue for roadworthiness.

Uneven trailer tyre wear causes

Wear pattern	Possible cause
Both shoulders worn	Low pressure, overload or unsuitable operating pressure
Centre tread worn	Excessive pressure or incorrect pressure setting
Inner edge worn	Axle alignment, suspension or geometry issue
Outer edge worn	Alignment, loading or cornering stress
One tyre wears faster	Brake, bearing, axle or local suspension issue
Scalloped wear	Suspension, bearing, balance or alignment problem
Feathered tread	Tracking or alignment problem
Patchy tread damage	Worksite impact, debris or mechanical issue

For example, if the inside edge of one tyre is disappearing faster than the others, fitting a new tyre without inspecting the axle and suspension may simply create the same wear pattern again.

What to inspect alongside an uneven tyre

• axle alignment
• suspension springs
• shackles and bushes
• wheel bearings
• hubs
• brakes
• wheel nuts
• rim condition
• tyre pressure
• load distribution

If your trailer has developed unusual tyre wear, Halco’s trailer servicing team can inspect applicable tyres, wheels, bearings, suspension, axles and related running gear.

5. The tyre keeps losing pressure

Repeated pressure loss is a trailer tyre warning sign that should be investigated rather than repeatedly corrected with an air compressor.

Possible causes include:

• a puncture
• damaged valve
• leaking valve stem
• rim damage
• bead-sealing problem
• sidewall damage
• corrosion around the rim
• tyre damage
• incorrect tyre fitment

A tyre that repeatedly loses pressure can run hotter than intended. Low pressure also changes how the sidewall flexes and how the tyre carries the trailer load.

Pressure-loss decision table

Situation	What to do
Pressure drops slightly over a long period	Check valve and monitor
Pressure drops noticeably between trips	Inspect for a leak
Pressure drops during one working day	Stop and inspect
Tyre is visibly soft	Inflate only to the correct specification and investigate
Valve leaks	Repair or replace valve
Rim is damaged	Inspect rim before refitting tyre
Tyre loses pressure after a puncture	Professional inspection recommended
Pressure loss occurs with visible sidewall damage	Replace tyre

Do not assume that repeatedly topping up a tyre makes it safe for another loaded trip.

6. The tyre shows heat, impact or worksite damage

Heat marks, impact damage, chunks missing from the tread, cuts, embedded objects and abnormal deformation can all indicate that a trailer tyre has experienced conditions outside normal operation.

This is especially relevant for trailers used around construction sites, farms, landscaping jobs, gravel roads and industrial yards.

A work trailer can encounter:

• nails and screws
• sharp rocks
• broken concrete
• kerbs
• potholes
• metal debris
• timber fragments
• rough shoulders
• deep ruts

A tyre does not necessarily need to be completely flat before it becomes unsafe.

Worksite damage checklist

Damage	Replacement consideration
Deep cut	High
Sidewall impact	High
Missing tread section	High
Embedded object	Inspect before removing
Heat discolouration	Inspect immediately
Repeated punctures	Investigate tyre type and route
Rim impact	Inspect tyre and rim together
Blowout damage	Inspect nearby trailer components

After a blowout, do not inspect only the replacement tyre. The failed tyre can damage the guard, wiring, brake components, mudguard, suspension or other nearby trailer parts.

7. The tyre rating no longer suits the trailer

A tyre may need replacing even when its tread and appearance look acceptable if its size, speed rating or load rating is unsuitable for the trailer’s intended use.

The current Vehicle Standards Bulletin 1 from the Australian Department of Infrastructure states that trailer tyres must have suitable specifications for the trailer’s intended use, including size, speed rating and load rating.

VSB 1 also specifies tyre-placard information for applicable trailers, including recommended tyre size, load rating, speed rating and cold inflation pressure.

Australian Government – Vehicle Standards Bulletin 1

When rating becomes a replacement issue

Situation	Why it matters
New trailer has different working load	Existing tyres may not suit
Trailer is now used for heavier equipment	Load rating needs review
Tyres are below required rating	Replace with suitable specification
Different tyre size fitted	Fitment needs verification
Speed rating differs	Confirm suitability
Trailer modification changes mass	Recheck tyre requirements
Towing application has changed	Reassess tyre specification

This is particularly important for businesses whose trailer has gradually moved from light-duty use into machinery, building materials, landscaping, vehicle transport or other heavier applications.

8. The tyre or rim shows age, vibration or repeated faults

Persistent vibration, wobble, repeated punctures or an ageing tyre-and-rim combination can indicate that replacement is needed even when the tread initially appears acceptable.

The problem may not be the tyre alone. A bent rim, damaged hub, worn bearing, wheel imbalance or suspension issue can create symptoms that appear to be tyre problems.

Check these components together

Symptom	Also inspect
Vibration at speed	Tyre, rim, hub and wheel balance
Wobble	Wheel nuts, hub, bearing and rim
Repeated punctures	Tyre type, pressure and worksite conditions
Tyre bead leak	Rim and valve
One wheel repeatedly overheats	Brake, bearing and hub
Tyre wears after replacement	Axle and suspension
Spare keeps ageing unused	Spare tyre condition and storage
Vibration after impact	Rim, hub, tyre and suspension

If the same tyre position keeps developing faults, investigate the wheel position rather than simply replacing the rubber each time.

What should be included in a trailer tyre inspection checklist?

A trailer tyre inspection checklist should cover every tyre, the spare, pressure, tread, sidewalls, age, load rating, rims, wheel nuts, wheel position and signs of heat or abnormal wear.

Walk around the trailer rather than checking only the tyres on the visible side.

Trailer tyre inspection checklist

Before every loaded trip:

• ☐ Check every tyre’s cold pressure.
• ☐ Check the spare tyre.
• ☐ Look across the entire tread.
• ☐ Inspect both visible sidewall areas.
• ☐ Look for cracks and perishing.
• ☐ Check for bulges and bubbles.
• ☐ Look for cuts or exposed cords.
• ☐ Check for embedded objects.
• ☐ Compare wear across all tyres.
• ☐ Check for tyre-to-guard rubbing.
• ☐ Inspect visible rim damage.
• ☐ Check wheel nuts are secure.
• ☐ Confirm tyre size and load rating are suitable.
• ☐ Check for recent pressure loss.
• ☐ Look for signs of overheating.
• ☐ Recheck after the first part of a long trip.

For commercial operators, add the inspection date, trailer identification, tyre position, tyre condition and any repair or replacement action to the service record.

What trailer tyre pressure should you check before towing?

Trailer tyre pressure should be checked when the tyres are cold and should follow the trailer, tyre or manufacturer specification applicable to the setup. Do not choose pressure simply because it is the number used on your passenger vehicle.

VSB 1 states that applicable trailers with a GTM not exceeding 3,500 kg must have a tyre placard showing, among other information, the manufacturer’s recommended cold inflation pressure.

The correct pressure should also be considered alongside load. A trailer carrying a mower, machinery, soil, building materials or a vehicle may operate under very different loads from an empty trailer.

Trailer tyre pressure before towing

Check	Why
Cold tyre pressure	Gives a consistent starting measurement
Manufacturer recommendation	Matches the trailer’s intended setup
Load being carried	Affects tyre loading
Tyre load rating	Determines suitability for the application
Spare pressure	A flat spare is useless during a breakdown
Pressure on both sides	Helps identify uneven loading or leaks
Pressure after storage	Trailers can lose pressure while parked

Do not release air from a hot tyre simply because its pressure is higher after driving. Check pressures when cold and use the applicable specification.

When should you replace trailer tyres rather than repair them?

You should replace trailer tyres rather than continue using them when they have structural damage, exposed cords, serious sidewall cracking, bulges, unsafe tread, unsuitable load rating, severe heat damage or other conditions that make them unsuitable for road use.

Some punctures can be repaired depending on their location and the tyre manufacturer’s requirements. Sidewall and structural damage should not be treated like a simple tread puncture.

Replace vs inspect table

Condition	Replace?
Tread at or below applicable minimum	Yes
Deep sidewall crack	Yes
Bulge or bubble	Yes
Exposed cords	Yes
Serious tread separation	Yes
Wrong load rating	Yes
Severe impact damage	Yes
Minor repairable tread puncture	Professional assessment
Uneven tread wear	Inspect cause and replace if required
Slow pressure loss	Diagnose first
Old but visually good tyre	Assess age and condition
Damaged rim	Inspect tyre and rim together

The Department of Infrastructure’s current VSB 1 Revision 6 is the appropriate government reference for applicable trailer construction and component requirements; state and territory requirements can also apply.

What are the common trailer tyre problems worth investigating?

The most common trailer tyre problems include low pressure, uneven wear, sidewall cracking, punctures, overloaded tyres, incorrect tyre specifications, heat damage, vibration and rim-related faults.

The important point is that tyre symptoms often connect to other trailer systems.

Common trailer tyre problems and possible causes

Problem	Possible underlying cause
Rapid tread wear	Overload, pressure or alignment
Inner-edge wear	Axle or suspension issue
Outer-edge wear	Alignment or loading
Centre wear	Excessive pressure
Shoulder wear	Low pressure or overload
Repeated punctures	Worksite debris or unsuitable tyre
Slow pressure loss	Valve, rim or puncture
One hot tyre	Brake or bearing issue
Vibration	Tyre, rim, hub or bearing
Tyre rubbing	Suspension, load or clearance issue
Cracking	Age, UV or storage
Blowout	Damage, pressure, load, age or heat

If several tyres are developing the same problem, do not treat them as separate failures. The trailer itself may need inspection.

What should you do after replacing trailer tyres?

After replacing trailer tyres, check the wheel and rim condition, confirm the tyre specifications, set the correct cold pressure, inspect wheel nuts and monitor wear during the first trips.

If the old tyres showed unusual wear, replacing them should be followed by diagnosis of the cause. Otherwise, the new tyres may develop the same fault.

Post-replacement check

1. Confirm the tyre size.
2. Confirm the load rating.
3. Confirm the speed rating.
4. Check rim compatibility.
5. Set cold pressure correctly.
6. Check wheel-nut security according to the trailer manufacturer’s requirements.
7. Inspect clearance around the tyre.
8. Check brakes and bearings if the old tyre showed heat damage.
9. Monitor tread wear after use.
10. Record the replacement date and tyre details.

For businesses, recording tyre replacements alongside trailer servicing makes it easier to identify recurring problems across a trailer or fleet.

Conclusion

The eight main trailer tyre replacement signs are low or damaged tread, cracking, bulges, uneven wear, repeated pressure loss, heat or impact damage, unsuitable tyre ratings and persistent vibration or tyre-related faults.

A tyre should not be judged by tread depth alone. Pressure, age, load rating, sidewall condition, wear pattern, rim condition and the trailer’s actual workload all matter.

For trailer owners across Warragul, Melbourne, Gippsland and regional Victoria, Halco Trailers can assist with trailer parts, servicing and repair inspections. If a tyre is damaged, repeatedly losing pressure or wearing unusually, have the cause checked before your next loaded trip.