One of the most frightening things that can happen when you’re pulling a tag-along trailer is sway or fishtailing. I was once driving behind my husband when he was pulling the horse trailer. He was going down a steep hill on the way to Vermont and he was going too fast. The trailer started to sway. From where I was sitting, it was incredibly scary. Luckily, he’s an excellent driver and he got the rig under control, but for a few minutes I was wondering if I was going to lose horse and husband!
There are several things that can cause your trailer to fishtail.
- Being passed by a large vehicle
- Sudden evasive maneuvers
- Driving downhill
- Driving too fast
- Tires that aren’t properly inflated
- Poor weight distribution – when towing a trailer with a ball mount hitch the trailer’s tongue weight is transferred to the tow vehicle. The additional weight inn the back pushes down the rear end of the tow vehicle, simultaneously raising the front. As a result the rear axle has to handle both the trailer tongue weight and the additional load that occurs as weight is transferred from the front axle.
If you experience trailer sway, it can be difficult to bring under control, even if you do everything right. Keeping forward motion and tension on the hitch can help prevent loss of control from trailer swa.The best thing you can do to straighten out a sway is to hold the steering wheel steady, take your foot off the gas, and apply the trailer brakes only (not the car brakes!) This slows the trailer behind you and keeps the tow vehicle going forward which should straighten out the combination.
Use a lower gear to travel up or down steep hills. If you feel the trailer pushing the vehicle when you are going downhill, apply the hand brake to slow the trailer. On long uphill grades, downshift the transmission and slow to 45 mph or less to reduce the possibility of overheating.
Preventing Trailer Sway
The better choice is to prevent trailer sway from occurring by installing a hitch that works with you to stabilize your trailer and to drive defensively. When we experienced the fishtailing, we were pulling with just a standard hitch (as installed by the trailer company). Shortly after that we installed a hitch that would help prevent sway. After much research, my husband chose the Equal-i-zer Hitch which provides both weight distribution and anti-sway control.
Weight distribution hitches add spring bars to the hitch system which are used to apply leverage between the tow vehicle and the trailer. This leverage transfers the load sitting on the rear of the vehicle to all the axles of the vehicle and trailer. With the trailer tongue and rear cargo load distributed between the axles, the vehicle is leveled off and performance is greatly increased. Weight distributing systems should be used any time the trailer weighs more than 50% of the vehicle weight.
Sway control devices help prevent the pivoting motion that can occur between tow vehicle and trailer.
The difference with the Equal-i-zer hitch was like night and day. With the hitch, my trailer and truck ride like a single unit with no fishtailing. At this point, I can’t imagine driving my trailer without it. Yes, it takes a few more minutes to hitch and unhitch, but once you get the hang of it, it’s really not a problem. Especially when you consider the benefits.
A good resource for trailer and towing questions and information is www.mrtruck.net.
Here’s what the Website says about the Equal-i-zer hitch:
There are several good WD hitches available. I like Equal-i-zer because their hitch works as a Weight “Distributing Hitch and Anti-sway bar all in one and they are one of the only ones that don’t require holes drilled into the trailer hitch and they work with surge brakes like you find on boat trailers and some horse trailers. The Anti-sway system is incorporated into the spring arms as they drag across the L bracket on the trailer end and the hinged trunnions where they bolt to the head. This causes friction and slows down the reaction at the hitch. They hook up easy and fast without holes in the trailer hitch. The friction anti-sway bars that are an option on some WD hitches apply pressure with a sliding plate clamp system that aren’t to be used in the rain or snow. During rain and snow you need anti-sway the most. Equal-i-zer WDH are a little over $500 so they aren’t the cheapest or the most expensive, you can order direct from the manufacture or a lot of RV and trailer dealers sell them. I use mine on all the different trucks I test from Quadrasteer Suburban to Hummer H2. I’d be in trouble if I had to drill holes in all the trailers I borrow. A lot of bumper pull horse trailers have sheet metal across the V-hitch so you have to cut a small slit in the sheet metal for the brackets. Which is better than most WD hitches that have a wide clamp that is bolted or welded to the trailer frame for the spring bars to attach to with chains. Also instead of corrugated washers to adjust the angle of the head, Equal-i-zer uses a large solid pin with spacer adjustment that can’t slip.”
Other commonly used hitches include: