How To Connect A Trailer

When connecting a trailer to your towing vehicle, extra care must be taken to ensure that every step is executed correctly. Failure to comply with all instructions may result in faulty lighting or an accident due to the trailer disconnecting.

Step 1.    Inspect the towing vehicle's tyres, tow bar and tow ball to ensure their serviceability, rating and overall integrity. Every new Australian vehicle's tow bar will come with a compliance plate stating the tow bars maximum load limit and an overall tow rating of the vehicle in which the manufacturer states the tow bar can legally comply (as seen on the right.)  The capacity of your tow bar and coupling must be at least equal to the loaded mass of the trailer. A tow bar fitted to a vehicle built after January 1992 must be marked with its load capacity and either the vehicle model for which it is designed or the tow bar manufacturer's part number.

- Tow bar must not protrude dangerously from a vehicle, or have sharp corners that could be a safety hazard when no trailer is fitted to your vehicle.              

- Tow bar chain attachments must be able to withstand the rated load capacity of the tow bar.                   

- The safety chain attachments must be mounted adjacent to the tow coupling and arranged so as to maintain the direction of the trailer in the event of coupling failure or disconnection.     

Tow bars with a removable towing lug should be fitted with safety chain connections on the non-removable part of the tow bar. If the chain connections are on the removable lug then the lug must be restrained by an additional chain to prevent disconnection from the tow bar if the lug attachment rails. always ensure the pin is secure and the bolt is tight. 

Many tow balls also state their rating on the top or on the rim of the ball as seen in the picture on the right. (If in doubt, DON'T USE IT. Refer to your towing vehicles owner's manual or contact a qualified tow bar specialist for further inspection). Visit our page dedicated to tow ball safety requirements at:

Towbar Safety Tips


Tow bar compliance plate

 Towball Cover

Toeball covers are great for keeping excess dirt from your towball.

50mm Towball

A standard 50mm tow ball with a 3.5 ton rating

Step 2.    If the tow bar and tow ball are in good working order, attach the trailer coupling over the towing vehicle's tow ball checking both visually & physically that the trailer will not disconnect for any reason whatsoever. (A 50mm tow ball is standard for all hire trailers in Australia.) 

Ensure the coupling locking latch is in the locked position or the trailer will bounce off the towball whilst driving.

Step 3.    The trailer must now be connected to the towing vehicle using a safety chain to prevent the trailer from disconnecting from the towing vehicle in the event that the coupling should come loose from the tow ball or during an accident. The chain(s) must be connected to the towing vehicle using D-shackles that are rated to withstand the combined weight of the load and the trailer.  (Trailers towing over 2.5 ton ATM must be connected to the towing vehicle using 2 safety chains.)

The best way to connect the chains from the trailer to the towing vehicle is in a crossed over pattern where the chains act as a cradle to prevent the trailer coupling from hitting the ground in the event of disconnection.  Ensure there is enough slack for maneuvering and cornering.

Trailers over 2.5 tonnes ATM must have two safety chains of designation of 3500 kg complying with Australian Standard AS 4177.4-1994 or Australian Standard AS 4177.42004;

Allow only enough slack in the chain(s) for turns, so that the trailer will not hit the ground when disconnected from the tow ball. This will ensure the trailer remains with the towing vehicle and doesn't roll away and cause further harm.

Important: the chain(s) should never drag along the ground! (This will weaken the chain(s) over time causing it to break much easier under pressure)

Double back excess chain to prevent dragging.


Two chains are crossed under the tow ball to catch the coupling if the trailer disconnects.


Step 4.    Connect the power cable plug from the trailer into the towing vehicle input ensuring all lightsare working correctly. (These include: Stop lamps (Brake lights), indicators, parkers and number plate lights.

If the lights are not working or cutting in and out, refer to out tech talk page to help diagnose the problem as:


Step 5.    Check that the jockey wheel is in the raised and locked position, ensure the hand brake (where applicable) is off and the coupling brake lockout is in the open position to engage braking on over-ride braking systems.

Always remember to raise the jockey wheel to prevent damage.

When raising the jockey wheel, ensure the wheel is to the rear and that the handle is tucked in to prevent damage on steep driveways.

Always ensure the handbrake is off whilst driving or excessive damage to the brakes may occur.

 You are now connected and ready to go. It is good practice to always check that both the towing vehicle and the trailer's tyres are inflated to the manufacturers specifications before towing.