What you need to know about towing equipment
Certain equipment is mandatory for towing any trailer. This includes obvious things like tow bars and trailer wiring connectors.
Just because the car you bought came with a tow bar, don’t automatically assume that it’s suitable for a caravan or heavy trailer. Many are only intended to tow light trailers and will be unsafe for heavy use. The tow bar’s ID plate will list its specifications.
- Tow bars are available from several sources.
- Most commonly they come from a specialist tow bar manufacturer or as original equipment from the vehicle manufacturer.
- There may appear to be a price benefit in buying non-genuine, but do your homework as the vehicle manufacturer’s towing package may be more than just a towbar. Some include things like heavy-duty suspension and additional transmission oil coolers to maximise safety and vehicle durability.
- If the tow bar tongue or ball obscures the rear number plate, it must be removed when not in use.
Load distribution/levelling devices
- Load distribution devices are used to return the tow vehicle’s attitude to as near level as possible once the trailer has been connected.
- This benefits steering control and braking.
- They are available in a range of sizes and styles to suit the particular application.
- Some vehicle manufacturers specify load-levelling devices as a mandatory part of their towing package.
- However, some specifically advise against their use due to tow bar and vehicle design issues.
- Using a load distribution hitch with a vehicle or tow bar not designed for it can damage the vehicle and/or the tow bar.
- Load distribution systems are not intended to compensate for excessive ball or rear axle loads or to correct poor trailer loading.
- Other levelling devices include height adjustable shock absorbers and original equipment self-levelling suspension systems.
- Before attempting to tow heavy loads with self-levelling suspension systems, or using weight distribution devices with them, the advice of the vehicle’s manufacturer should be sought.
Light trailers must have safety chains to link the trailer to the tow vehicle.
- They must be strong enough to hold it in the case of an accidental disconnection.
- They must have sufficient length to allow the normal articulation of the trailer but be short enough to prevent the drawbar hitting the ground.
- Trailers up to 2500 kg ATM are required to have one safety chain.
- Trailers from 2,500kg to 3,500kg must be fitted with two.
- Trailers with an ATM of greater than 3,500kg must have two safety chains made from T grade chain that meets the requirements of AS 2321 and have a break load limit exceeding the trailer’s ATM.
- Where two safety chains are fitted they should cross diagonally under the drawbar i.e. the right safety chain will connect to the left attaching point on the towbar and the left chain attaches to the right side of the tow bar.
Safety chain shackles
It's common practice to use shackles to attach trailer safety chains to vehicle tow bars. The shackle must have adequate strength to retain the trailer in the event of a disconnection (with a margin for safety).
Queensland's Department of Transport and Main Roads recommends that a shackle used for this purpose:
- complies with Australian Standard AS 2741-2002 “Shackles” or other equivalent recognised standard; and
- has a break load limit *at least 1.5 times greater than the trailer’s ATM.
- However, this is a recommendation, not legislation. We strongly recommend using a load rated shackle.
- Shackles are only marked with their Working Load Limit.
- The Breaking Load Limit of a compliant shackle is generally six times its Working Load Limit.
AS 2741-2002 compliant shackles will be legibly and permanently marked with the following information:
- The manufacturer’s name or trademark
- Quality grade of the shackle, e.g. (‘M’ or ‘4’, ‘S’ or ‘6’)
- Working Load Limit (WLL) or Rating; and
- Identification marking in order to correlate the shackle to the test certificate
The following guide will assist in selecting an appropriate shackle:
||Shackle pin size
|Up to 4500
|| ‘S’ or ‘6'
|Up to 4000
|| ‘S’ or ‘6'
|Up to 3000
|| ‘S’ or ‘6'
|| 13mm 'M' or '4'
|Up to 2000
|| ‘S’ or ‘6'
|| 10mm 'M' or '4'
|Up to 1000
|| ‘M’ or ‘4'
- Specialised shackles of this type may not be available from hardware stores etc. You may need to consult a caravan or trailer accessory outlet.
- Both Dee and Bow shackles of the appropriate grade are acceptable. Bow shackles provide for greater angular usage compared to Dee shackles.
- Unless otherwise indicated, stainless steel shackles are unsuitable for safety chain connections due to the material’s generally low resistance to bending stresses.
- Un-rated shackles should not be used as their load limits are unknown.
- Trailers up to and including 750kg GTM do not require brakes*
- Trailers not over 2,000kg GTM must have brakes that operate on at least one axle
- Override brakes are acceptable on trailers up to and including 2,000kg GTM
- Trailers over 2,000kg GTM are required to have brakes that apply automatically if the trailer becomes detached from the towing vehicle
- Trailers over 2,000kg GTM must have brakes on all wheels
- Brakes other than override systems must be able to be operated from the driver’s seat
* Unless the tow vehicle specifies otherwise.
Types of trailer brake systems
The cost and complexity of trailer brake systems will vary depending on the application.
- Override brakes are self-contained in the trailer and are activated by the slowing of the towing vehicle. Override brakes cannot be applied independently of the tow vehicle.
- Electric brake systems require the installation of a control unit. They can usually be applied independently of the tow vehicle’s brakes and incorporate a system that allows the trailer braking force to be adjusted.
- Brake systems that apply automatically in the event of a trailer disconnection are known as Breakaway Systems. Light trailers with a breakaway system will often have a battery on the trailer to maintain brake operation for a designated period.
Extended towing mirrors
Extended towing mirrors are required when the vehicle’s existing mirrors cannot provide a clear view past the caravan or trailer. There are a number of variations on the market and you will need to choose the type that best fits your vehicle and needs.
Rear view cameras can be used to provide a view of the blind spot directly behind a caravan. However, it can be difficult to judge distances with them and they are definitely not a substitute for extended mirrors. They may also be of some benefit when reversing or manoeuvring.
Do not overtake signs
Vehicles, including combinations of tow vehicles and trailers, exceeding 7.5 metres in length may be fitted with “Do not overtake turning vehicle” signs. However if the vehicle exceeds 7.5 metres and needs to straddle a lane when turning at an intersection, these signs become mandatory. They are not permitted on vehicles less than 7.5 metres in length.
Upgrades and accessories
There’s a plethora of towing accessories and equipment on the market. Some may produce genuine benefits, while others may be of questionable value. And it can be difficult to readily determine which of those categories some of it fits into.
Some even constitute major modifications intended to make the vehicle do things it was never designed for. Be aware though that some will require certification and /or approval by the relevant transport authority, some may have insurance implications and will almost certainly impact the vehicle’s warranty cover (where applicable), and potentially its resale value.
Like a great deal of aftermarket equipment you’re likely to be largely on your own when it comes to determining its value or appropriateness.