Trailer starts swaying while towing: what to do?

Trailer sway, also called fishtailing, happens when the trailer oscillates side to side behind your vehicle. It can escalate quickly and cause loss of control, so knowing the right response is essential.

What is happening

Sway often starts when the trailer is overloaded at the rear, the weight is distributed unevenly, the hitch is too high, or you are driving too fast for conditions. Crosswinds, passing trucks, and sudden steering inputs can trigger it.

Emergency warning

If the sway becomes severe and you cannot control the vehicle, call local emergency services immediately. Do not wait until you are in a dangerous situation.

What to do first

1. Ease off the accelerator. Gradually reduce speed by lifting your foot, not by braking hard. Hard braking can make the sway worse.
2. Keep the steering wheel steady. Hold it firmly and avoid quick corrections. Look straight ahead and keep the vehicle pointed in your lane.
3. Do not accelerate. Speeding up might feel like it stabilizes the trailer, but it usually makes sway more violent.
4. If you have a trailer brake controller, apply the trailer brakes only. This can help straighten the trailer. Do not use the tow vehicle's brakes alone.
5. Pull over safely. Once the sway is under control, slow down and stop in a safe place. Check the hitch, safety chains, tire pressure, and load distribution.

What NOT to do

• Do not slam on the brakes.
• Do not jerk the steering wheel to correct the sway.
• Do not accelerate to try to outrun the sway.
• Do not continue driving if the sway keeps happening.

When to call for help

Call emergency services if the sway causes you to leave your lane, if you cannot regain control, or if there is a collision. If the trailer is unsafe to tow, call a professional towing service.

What to monitor

After you stop, inspect the tires for damage or low pressure, check that the hitch is secure, and confirm the load is balanced with more weight toward the front of the trailer. Also check that the trailer is level with the tow vehicle.

How to prevent it

• Load the trailer with about 60% of the weight ahead of the axle and 40% behind it, and keep the tongue weight within the manufacturer's specified range.
• Use a weight-distribution hitch if your setup requires it.
• Keep tires properly inflated and in good condition.
• Drive at a safe speed for conditions, especially in crosswinds or when passing large vehicles.
• Practice smooth steering and braking inputs.

If sway happens, stay calm, ease off the gas, and keep the steering steady. After you are safe, address the cause before continuing your trip.

This is general information and not a substitute for professional driving advice. In an emergency, call local emergency services.