Whether you’re using a sleek covered car transporter trailer to move valuable motors or hauling garden waste in a basic utility trailer, regular trailer maintenance is essential for safety, performance, and long-term reliability. A well-maintained trailer won’t just save you from costly repairs — it also helps prevent dangerous breakdowns and ensures your load reaches its destination in one piece.
Here’s everything you need to know about maintaining your trailer, with specific advice for car transporter trailers and other car-hauled types.
1. Tyre Checks: More Than Just a Quick Look
Trailer tyres often get overlooked, but they take just as much punishment as car tyres — sometimes more.
- Pressure: Keep tyres inflated to the recommended PSI, which is often listed on a plate near the wheel arch or in the trailer manual. Underinflation can cause blowouts, especially under heavy load.
- Tread Depth: Legally in the UK, trailer tyres must have a minimum tread depth of 1.6mm. If they’re wearing thin, replace them before your next journey.
- Cracking and Age: Tyres can crack or degrade even if they’re not worn. Many trailer tyres age out before they wear out — if they’re over 5 years old, it’s time to replace them.
- Spare Wheel: Don’t forget to carry a properly inflated spare and the right tools for a quick change.
2. Lighting & Electrics: Stay Legal and Safe
Lighting faults are one of the most common causes of trailer MOT fails and roadside stops.
- Connectors: Before each trip, test all lights — brake, indicators, tail lights, number plate lights — after plugging into the towing vehicle.
- Corrosion: Water and grime can get into plugs and sockets, especially with covered car transporter trailers. Use a contact cleaner and a dab of petroleum jelly or dielectric grease to prevent rust.
- Wiring: Inspect cables for damage from wear, sharp edges, or rodents. Replace damaged sections with waterproof connectors and secure them away from moving parts.
3. Brakes & Hitch Mechanism: Vital for Safety
Car transporter trailers are typically braked trailers, meaning they have their own braking system. These need just as much attention as your vehicle’s brakes.
- Brake Shoes & Drums: Check for wear, rust, or contamination. If the trailer pulls to one side when braking, get it inspected immediately.
- Breakaway Cable: Legally required for braked trailers. Make sure it’s correctly fitted, free of rust, and not frayed.
- Hitch Coupling: Inspect for wear and ensure the hitch engages smoothly and locks securely onto the tow ball. Lubricate moving parts to keep operation smooth.
For unbraked trailers (under 750kg), ensure the coupling mechanism is clean, free-moving, and secure. Always double-check that the trailer is properly latched onto the towball and the safety chain is attached.
4. Chassis and Frame: Look Beneath the Surface
Over time, trailers – especially those exposed to the elements – can suffer from rust and structural issues.
- Rust Prevention: Clean the chassis regularly and touch up any chips or scrapes with rust-resistant paint.
- Welding & Joints: Check for cracks or loose welds. These can be dangerous if left unchecked and should be repaired by a professional.
- Flooring: On car transporter trailers, inspect the internal floor for any signs of rot (in wooden floors) or corrosion (in aluminium/steel). A weak floor can be catastrophic when transporting heavy vehicles.
5. Suspension & Axles: Keep Things Smooth
Most car transporter trailers use either leaf spring or torsion bar suspension.
- Check for Sagging or Noise: Excessive bounce or knocking noises may indicate a problem with the suspension.
- Axles: Make sure they’re straight and rust-free. Bent axles can lead to uneven tyre wear and poor handling.
6. Interior (for Covered Car Transporters)
If you’re using a covered trailer for high-value vehicles:
- Doors & Ramps: Ensure rear doors and loading ramps operate smoothly and securely latch when closed.
- Ventilation: Some enclosed trailers include ventilation to prevent condensation — keep vents clear.
- Cleanliness: Regularly sweep and wash the interior to avoid debris scratching car paint or damaging tyres during transport.
7. General Maintenance Tips
- Grease Moving Parts: Apply trailer-specific grease to wheel bearings, coupling heads, and jockey wheels regularly.
- Jockey Wheel: Keep the winding mechanism smooth and the wheel in good condition — a failure here can make hitching up a nightmare.
- Storage: If you’re parking up the trailer for a while, store it on level ground, chock the wheels, and cover it if possible.
Final Thought
Whether you’re transporting a classic car in a pristine covered trailer or taking garden clippings to the tip, your trailer is an essential tool. Treat it well, and it’ll serve you for years to come. Set a regular maintenance routine, especially before longer trips or periods of storage, and don’t ignore the signs of wear.
For peace of mind, consider an annual service with a trailer specialist — they’ll spot issues you might miss.
Safe towing!