By Gail Marsh
What does a dog’s tail have to do with towing an RV? Turns out, a lot! Not knowing about the “wagging dog’s tail” can mean disaster. In fact, “the tail wagging the dog” syndrome is a main cause of trailer accidents today. Trailer tail-wagging is one of the reasons why many would-be RVers quit RVing after just one season.
Dog? Tail? What?
Imagine towing a travel trailer behind your truck. Think of the trailer as the “dog’s tail.” Your truck is the “dog.” Sometimes when traveling down the road, the travel trailer will begin to sway back and forth (also called fishtailing). This puts immense pressure on the rear end of the truck or tow vehicle. The side-to-side trailer movement can become so severe that the truck driver loses control. The trailer can flip, bringing the tow vehicle right along with it! Yipes! Even if the trailer doesn’t cause the tow vehicle to flip, the trailer can break free of the ball hitch and cause major damage to the trailer. Worse, the renegade trailer can potentially cause major damage – even death – to others on the highway.
Why does trailer “tail-wagging” happen?
“Fishtailing” or “tail-wagging” happens because in most cases the trailer far outweighs the tow vehicle’s weight. A travel trailer can weigh anywhere from 3,000 lbs. to more than 12,000 lbs. Compare that to your truck’s weight and you’ll see how the force of trailer sway can affect the truck driver’s ability to control the situation.
There are other factors that can contribute to trailer sway. Wind, for instance. A stiff crosswind can cause side-to-side trailer movement, as can the gust of wind that hits your rig when passed by a high-profile, fast-moving 18-wheeler.
Low tire pressure can cause the tire sidewalls to compress on the tow vehicle and/or trailer, too. Check tire pressure several times along your route to maintain maximum tire pressure, especially in the rear tires.
Improper loading or excessive weight can also cause “tail-wagging.” Pay special attention to the tongue weight on your trailer. The tongue weight should be no more than 15 percent of the total weight of the trailer. Don’t overload the back of the trailer, either. Too much weight can cause the trailer to “squat” and begin to sway.
Preventing trailer sway
Purchase special trailer sway bars or a sway hitch. Ask your local RV dealer for recommendations. Check product reviews online or ask other RVers what they’ve found to lessen or prevent trailer sway. There are several fine products specially designed to prevent, lessen, and/or eliminate “dog tail-wagging.”
There is one additional thing you can do to address the problem of trailer sway – and it’s free! Slow down. Many trailer tires are only rated for a maximum speed of 65 mph. Just because you’re allowed to travel faster in some states doesn’t mean you should – especially when towing a travel trailer. Slow down.
Watch this video to see a trailer “tail-wagging.” Yikes!
Stay safe out there! And don’t let the tail wag the dog!
RV Education 101 Online videos, including how to tow trailers, here.