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Prevent caravan sway Rockhampton
 

Caravan Sway and How to Prevent it HAC Rockhampton


Is your caravan doing the fish tail dance? Swaying and shaking with loss of control is a major cause of caravan accidents. Read on to discover the remedy.

What is Caravan Sway?


One of the most common causes of caravan sway is uneven weight distribution along with an careless packing technique. A good rule of thumb is to place all heavy items as close as possible to the axles and NEVER at the rear of the caravan.

Steps to Reducing Caravan Sway


Reducing caravan sway, also called yaw, demands minimising its causes – and only then by adding devices promoted as reducing the problem. Read on…

Consider the geometry. A caravan‘s sway is caused by its tow hitch being located a distance behind the tow vehicle’s rear axle. When the tow vehicle yaws in one direction that overhung hitch causes the caravan to sway in the other direction.

Likewise, caravan sway causes tow vehicle to sway. Do a simple line drawing and you will see the tow vehicle heading in one direction and the caravan in the opposite direction.

 

Electric Brake Controllers and the Law


Sway energy is dampened by the following: friction at the tow ball, tow vehicle rear-tyre tread distortion and wind resistance. Swaying that lasts for two to three cycles is irritating. This sway, however, is usually harmless. As long as it stops within those two to three cycles. A friction sway damping device will be useful here.

If the swaying does not cease within two to three cycles, its source must be located and rectified before adding any sway damping device. Adding bits and pieces of remedial systems is counterproductive if the cause is not located and fixed first.

Begin Sway Cause Investigation - the Tow Ball


Greasing your tow ball is not a good idea, you need it to grip, not slip! Investigate the Alko AKS Stabiliser 50mm 3.5t tow ball with 4 special friction damping pads. This device is a good place to begin solving and preventing Caravan Sway.

Limitations of Friction Based Anti-sway devices

These friction devices are most effective at speeds of up to 60km/h with the benefit reducing as road speed increases. Not everything you need but better than having a slippery greased tow ball.

Practical methods of Reducing Caravan Sway


An average tow hitch overhang which is the distance from the rear axle to the tow ball is 1.25 metres for Australian vehicles. If your tow hitch has excess overhang, have a new hole drilled accordingly. Every centimetre of reduction is worth having. Utes with extended chassis and/or tow hitches are at major risk.

Best case is to have the loaded tow vehicle heavier than the loaded caravan. Be aware, however, that with caravans, it's their length, and where weight is distributed along that length that primarily affects the tendency to sway. Moreover, the longer the caravan, the lower its safe towing speed.

With long caravans, let’s look at over six metres or app. 20 ft. you need to have all heavy items as close as possible to the axles. Never load anything heavy at the extreme rear. It’s a bad idea to have spare wheels on a caravan‘s rear wall. Their actual weight maybe 40 kg or so. Their dynamic weight, however, becomes greater than 120 kg. If your caravan has them on the rear, reposition them in a slide-out cradle underneath the caravan‘s floor putting them as close to the axle as possible.

An Insight to Tyre Pressures and Sway


For towing Increase the tow vehicle’s rear tyres pressure by 5-7 psi or 30-50 kPa. Some misinformed caravanners increase the tow vehicle’s front tyre pressure as well as the rear. NEVER do this as doing so seriously reduces stability. Use the vehicle maker’s recommended front tyre pressure as for normal driving. NEVER inflate the front tyres higher.

Reducing Caravan Sway by Design Loading


An Australian-built caravan is now typically 6.0 to 6.5 metres in length. Its unloaded weight is typically 2100-2200 kg. The laden mass is typically 2500-3500 kg. These weight figures are an indication only some, however, are greater than 4000 kg plus. Bear in mind that excess length is even more of a stability issue. Excess weight is now a major issue for the newer generation of tow vehicles.

What is Tow Ball Weight and what are its Consequences?

Tow ball weight, or Tow Ball Mass is the weight applied from your caravan to the Tow Ball on your tow vehicle. When you are towing, the bulk of the trailer weight is taken by its wheels, and a small portion of it is passed onto the tow vehicle via the Tow Ball.

Low Tow Ball mass increases the probability of sway that is not self-correcting. You may read RV Books that can (legally) only suggest owners follow the makers’ recommendations. It certainly does not, however, endorse such recommendations. Research plus more research and nail down what is the right Tow Ball loading for your situation.

Tow-Pro Elite Electric Trailer Brake Controller


It is now mandatory for all caravans heavier than 2000kg be fitted with an electric brake controller to provide the ability to adjust the strength of the trailer braking system. Some electric brakes can operate the trailer brakes independently of the vehicle brakes which aid in controlling caravan sway. Some controllers need to be mounted on the dash in a certain orientation to perform correctly and used for changing settings between different braking systems.

Tow-Pro Elite electric brake controller allows you to apply the brakes independently to the vehicle's brakes, which helps eliminate the dreaded caravan sway. The Tow-Pro Elite is AL-KO ESC and Dexter Sway Control System compatible, which are both very popular systems that are fitted on most new vans to reduce the incidence of sway.

The Tow-Pro Elite features a three-axis accelerometer and the main unit can be mounted in any orientation whilst still being able to accurately sense the brake level required. Once installed, you can adjust the control knob depending on the weight of the caravan.

What truly sets it apart from many other electric brake controllers on the market is that the Tow-Pro Elite is the only electric brake controller to offer two types of braking in the one unit. Offering selectable Proportional or User-controlled trailer braking modes, the user can choose the braking style required to suit the road or terrain conditions, vehicle type or personal preference.

The electric operated brakes under the control of the Tow pro electric brake controller are applied in proportion to the sway situation. It does this by creating resistance against the caravan moving out of line with the vehicle, meaning it is less likely to pivot on the tow ball unless the vehicle initiates the movement. They also retrofit AL-KO ESC and the Dexter DSC systems.

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Electric Brake and Wheel Bearing Service


Regular maintenance on your brakes and bearings is critical. We recommend a 10,000 kilometre or 12 month service to remove brake lining dust, lubricate the metal to metal friction points on the backing plate and adjust the position of the linings to ensure maximum efficiency of their operation in relation to the movement of the magnet lever arm. The wheel bearings should be washed out, inspected for wear, and if ok repacked with new grease and new hub seals. This is also an opportunity to inspect these components for signs of wear.

The magnet, depending upon its type, will have some wear indicator in its face. A round magnet has three screws countersunk into its wear surface and when it has worn down onto the heads of these screws the life of the magnet is near to its end.

An oval magnet usually has a series of ridges or impressions in it which similarly acts as a tell-tale sign on magnet life remaining. The difficulty with these wear patterns is that they may not be uniform or regular across the magnet face.

Yet any wear down beyond the indicator levels means that the operation of the magnets will cease as soon as the brake drum contacts the electric coil beneath the magnet surface. When you consider that you are inspecting the brakes with a view to the next 10,000 kilometres usually a conservative judgement is the safest.
 
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