Making a Trailer Tow Straight and Causes of Pendulum Swing
When fitting the axle, please ensure that both No.1 arrows are the same distance and both No.2 arrows equal the same distance. Having a slightly out of square chassis isn’t the end of the world as long as these dimensions are correct. These two dimensions are critical to a straight towing trailer.
If this has been done and the trailer continues to sway, the next thing to check is if there is too much rear weight i.e. pendulum swing. This is a common problem on boat trailers, usually caused by a heavy rear mounted outboard
motor with too much weight at the rear.
To correct this, shift the whole axle and spring setup further towards the rear until it stops swaying. If this then causes too much downward force on the tow ball, the next solution is to convert the trailer to a tandem or a tri-axle setup. This will give the trailer a broader axle area and more stability.