Trailer sway, that terrifying fishtailing sensation, is a nightmare scenario for any driver. The most important thing to remember when a trailer starts to sway is this: do not slam on the brakes or steer sharply. Instead, react calmly and deliberately, applying the trailer brake controller (if equipped) progressively and steering as little as possible, all while gradually reducing speed until the sway subsides.
Understanding Trailer Sway: A Threat to Road Safety
Trailer sway, also known as “fishtailing” or “yaw,” occurs when a trailer oscillates from side to side behind a towing vehicle. This can range from a slight wiggle to a violent, uncontrollable movement, potentially leading to loss of control, jackknifing, and even rollovers. Understanding the causes of sway is crucial to preventing it, but knowing how to react when it happens is paramount to ensuring safety.
Responding to Trailer Sway: A Step-by-Step Guide
The instinct to panic is natural when a trailer begins to sway, but staying calm and following these steps can help regain control:
- Remove Your Foot from the Accelerator: The first step is to immediately take your foot off the accelerator. Sudden deceleration can exacerbate the sway.
- Resist the Urge to Brake Hard: Hard braking is almost always the worst thing you can do. It shifts weight forward, decreasing traction on the trailer wheels and increasing the likelihood of further sway. Only brake hard as a last resort if a collision is imminent.
- Apply the Trailer Brake Controller (If Equipped): The trailer brake controller allows you to apply the trailer brakes independently of the tow vehicle brakes. Gradually increasing the trailer brake application can help pull the trailer straight. Adjust the brake controller sensitivity beforehand to ensure smooth application without locking up the trailer wheels.
- Steer as Little as Possible: Avoid abrupt steering maneuvers. Overcorrecting can amplify the sway. Focus on maintaining a straight line as much as possible. Small, gentle corrections may be necessary, but avoid aggressive steering at all costs.
- Gently Accelerate (If Safe and Necessary): In some cases, very gentle acceleration can help pull the trailer straight. This is a more advanced technique and should only be attempted if you have experience and the road conditions allow. Do not accelerate if it feels like it is making the sway worse.
- Slow Down Gradually: Once you’ve stabilized the sway, gradually reduce your speed. Find a safe place to pull over and assess the situation.
- Check Your Setup: After regaining control, carefully inspect your towing setup. Check the tongue weight, weight distribution, tire pressure, and hitch connection to identify potential causes of the sway.
Preventing Trailer Sway: Proactive Measures
Prevention is always better than cure. Taking proactive steps before and during your journey can significantly reduce the risk of trailer sway.
- Proper Weight Distribution: Ensure that approximately 10-15% of the trailer’s total weight is on the tongue. Too little tongue weight is a major cause of sway. Use a weigh scale to verify the actual weight distribution.
- Load Your Trailer Carefully: Distribute the load evenly inside the trailer, placing heavier items low and towards the front. This helps to lower the center of gravity and improve stability.
- Use a Weight Distribution Hitch: A weight distribution hitch transfers some of the tongue weight from the rear axle of the tow vehicle to the front axle and the trailer axle. This helps to level the towing setup and improve handling.
- Consider a Sway Control Device: Sway control devices, such as friction sway control or electronic sway control systems, can further dampen sway. Friction sway control adds resistance to the sway motion, while electronic systems use sensors to detect sway and automatically apply the trailer brakes.
- Maintain Proper Tire Pressure: Check the tire pressure on both the tow vehicle and the trailer tires before each trip. Underinflated tires can contribute to sway.
- Drive at a Safe Speed: High speeds can exacerbate sway. Reduce your speed, especially in windy conditions or when encountering large vehicles. Adhere to posted speed limits and always drive within your comfort level.
- Inspect Your Equipment Regularly: Regularly inspect your hitch, ball mount, safety chains, lights, and brakes to ensure they are in good working condition.
Frequently Asked Questions (FAQs) About Trailer Sway
Here are some frequently asked questions about trailer sway and how to address them:
1. What exactly causes trailer sway?
Trailer sway is primarily caused by an imbalance of forces acting on the trailer. This can be due to improper weight distribution (too little tongue weight is a common culprit), wind gusts, passing vehicles creating a vacuum effect, uneven road surfaces, or even sudden steering maneuvers.
2. How can I determine the correct tongue weight for my trailer?
The ideal tongue weight is typically 10-15% of the trailer’s gross trailer weight (GTW). You can determine your tongue weight by using a tongue weight scale or by visiting a weigh station. Be sure to account for all cargo loaded in the trailer when measuring.
3. Is a weight distribution hitch always necessary?
No, but a weight distribution hitch is highly recommended, especially for heavier trailers or when the tow vehicle’s rear suspension is significantly compressed by the tongue weight. It helps to level the towing setup, improve handling, and distribute the load more evenly across all axles.
4. What is the difference between friction sway control and electronic sway control?
Friction sway control uses a friction device to resist sway movements, providing a mechanical damping effect. Electronic sway control, on the other hand, uses sensors to detect sway and automatically apply the trailer brakes to counteract the sway. Electronic systems are generally considered more effective and responsive.
5. Can windy conditions cause trailer sway?
Yes, windy conditions are a major contributor to trailer sway. Crosswinds can exert force on the side of the trailer, initiating or exacerbating sway. Reduce your speed and be extra cautious in windy conditions.
6. What should I do if I experience sway when being passed by a large truck?
The vacuum created by a passing truck can cause a sudden pull on your trailer. Maintain a firm grip on the steering wheel and avoid sudden steering corrections. Gradually reduce your speed if necessary.
7. How often should I inspect my towing equipment?
You should inspect your towing equipment before each trip, as well as periodically during long journeys. Check the hitch, ball mount, safety chains, lights, brakes, and tire pressure to ensure they are in good working condition.
8. What is the role of trailer tires in preventing sway?
Properly inflated and well-maintained trailer tires are crucial for stability. Underinflated tires can increase the risk of sway. Check the tire pressure regularly and replace tires when they show signs of wear or damage. Use tires with a load rating appropriate for your trailer’s weight.
9. Can the height difference between the tow vehicle and the trailer affect sway?
Yes, a significant height difference can negatively impact handling and increase the risk of sway. The ideal setup is for the trailer to be as level as possible. Use a drop hitch or adjustable ball mount to achieve the correct height.
10. How does vehicle speed affect trailer sway?
Higher speeds generally increase the likelihood and severity of trailer sway. Reduce your speed, especially in adverse conditions or when towing a larger trailer. Driving slower provides you with more time to react and regain control if sway occurs.
11. What are the signs that my trailer is developing sway before it becomes severe?
Subtle signs include a feeling of looseness or instability in the steering, a slight “wagging” sensation in the trailer, or seeing the trailer in your mirrors move more than usual. If you notice these signs, slow down immediately and check your setup at the next safe opportunity.
12. What if I have tried everything and the sway persists or gets worse?
If you have tried the techniques described and the sway continues to worsen, your priority is safety. If possible, activate the trailer brakes forcefully with the brake controller in a controlled manner to bring the rig to an immediate stop on the side of the road. Then, carefully re-evaluate your entire towing setup, considering professional assistance if needed. Don’t continue driving in an unsafe condition.