How To Deal With Trailer Sway

Trailer sway is a terrifying and potentially deadly experience. Picture this: you're cruising down the highway, caravan in tow, on a sunny day. As you overtake a slow-moving truck, your caravan suddenly starts to swing wildly. Oncoming truckers veer to the side, and drivers behind you pull back, holding their collective breath. Inside your vehicle, the air is thick with tension as the caravan bucks, threatening to veer off the road.

In mere seconds, such an incident could turn catastrophic. 

Trailer sway—also known as yaw, fishtailing, or snaking—is more common than Australian accident statistics might suggest. Many caravan owners only discuss these harrowing experiences over an evening drink.

Stefan Drew, from Melbourne Trailer and Caravan Supplies, points out that remedies for trailer sway aren't always intuitive. "The severity of trailer sway can range from a brief, frightening event to a complete loss of vehicle control," he explains. Stefan advocates for electronic stability controls on caravans, which can help manage these situations before they escalate into accidents.

Why Does The Trailer Sway?

A swaying van or trailer can result from several factors, including underinflated tyre pressures, uneven or overloading, poor or uneven hitching, and inappropriate speed. Additionally, swaying can be triggered by oncoming vehicles or the low-pressure area encountered when passing another vehicle. 

This issue can occur even on good roads and in favourable weather conditions. Once a van starts to sway, the swinging or snaking motion can intensify around the hitch point's fulcrum. Fifth-wheelers have an advantage in this regard, as their tow point is positioned over the vehicle’s back axle, providing greater stability.

What Do I Do When It Does Sway?

What should you do when faced with sway? Most experts agree on a few key steps: stay calm and maintain a steady course, do not attempt to steer out of the sway, ease off the accelerator, and avoid braking the tow vehicle. Instead, apply the van's electric brakes gently using the dashboard controller. Pull over to check the load, tyres, and hitch level. Many sway problems often start with an uneven load that disrupts the rig's dynamics.

Vanners are responsible for ensuring the proper distribution and weight of their loads, as well as adhering to tow ball limits. It's essential to consult the vehicle's handbook for any specific towing restrictions.

In Australia, some new vehicles, like Ford's Ranger, come equipped with built-in trailer sway systems. For moderate sway, these systems activate the front brakes in an alternating left-right pattern to counteract the movement. In cases of severe sway, they reduce engine torque to zero and apply brake pressure to all four wheels, lowering the vehicle's speed below the trailer's critical speed.

Today, electronic stability controls for vans also exist. These systems monitor trailer sway or yaw and correct erratic movements by braking the wheels on one side of the van. They can be retrofitted to trailers equipped with electric brakes. For installation, consult AutoGuru or connect with one of the many car and towing experts across the country.