Everything you need to know about trailer sway

Trailer sway can be dangerous

If you’re towing a trailer or caravan, one of the worst things that can happen is for your trailer to wobble precariously back and forth, eventually falling on one side and dragging your vehicle down with it.

Trailer sway can be a major problem for many trailer owners, especially with New Zealand’s winding roads, and it can make driving and towing your trailer or caravan a rather nerve-wracking experience.

Knowing about trailer sway and how to deal with it is important, as it can quickly lead to whipping and create a dangerous situation for you and others on the road.

In some cases, it can be fatal.

What is trailer sway?

Trailer sway can be caused by gusts of wind, or the passing of big rigs.

It’s a side-to-side motion that occurs when towing a trailer at a specific pace. If you increase your speed, a constant side to side swaying motion is not typical and could lead to whipping, also known as snaking.

Whipping is a more severe and uncontrollable swing induced by a bigger weight in the back of your trailer.

Why does a trailer sway?

Caravan or trailer sway can be caused by a few things:

  • Underinflated tyre pressures.
  • Uneven or over-loading.
  • Poor, uneven hitching.
  • Inappropriate speed.
  • Oncoming vehicles.
  • Low pressure area when passing another vehicle.

Caused by a force of motion, it can occur on high quality road to the most careful of drivers.

MyAutoShop’s 5 steps to dealing with trailer sway

  1. Immediately let of the gas pedal to reduce your speed.
  2. you should slow down to and maintain a speed at least 10 miles per hour below the speed at which the sway or snaking/whipping was first noticed.
  3. Do not apply your brakes or speed up
  4. Hold your steering wheel in a straight ahead position
  5. As soon as possible, stop and reload your trailer with the heavier portion of your cargo in the front.

Trailer sway generally occurs due an unbalanced load that disrupts the rig’s dynamics.

If you’re in charge of a trailer, it’s your responsibility to be aware of the distribution and weight of the load and tow ball limits, and consult the vehicle’s handbook for any towing restrictions.

If you’re towing a caravan, be sure to read our article, Caravans: a driver’s guide.

To reduce the vehicle’s speed below the trailer’s critical speed, the engine torque is reduced to zero and braking pressures are applied to all four wheels.

When you’re towing, everyone’s safety on the road should be a priority. If your trailer doesn’t like certain conditions, things can get sour fast. If you have issues with trailer sway, keep these tips in mind, and be safe out there.

Finally, keep in mind that there are now electronic stability controls for vans. Get in touch with a MyAutoShop qualified mechanic to help point you in the right direction.