What causes trailers to swing out of control?

[Ready_fire_aim]

Ok y’all inform me on what causes trailers to swing back and forth like a pendulum on the highway. Twice recently I have seen guys pulling trailers hit a small bump then the trailer swings out of control side to side nearly causing a serious accident!

For years I have pulled boats, and I pull a 5x12 single axel utility trailer all the time. This has never happened to me…

What causes it?

 

[Bocephus123]

Too much tail weight behind the axle i believe.

 

[OK Corgi Rancher]

Too much weight towards the rear of the trailer.

 

[Perplexed]

Usually, the load isn’t centered over the trailer axles, and more often than not it’s too far back. Also exceeding the tongue‘s rated weight can cause sway to occur.

 

[OK Corgi Rancher]

 

[Bahick71]

It can be caused by lack of tongue weight, which goes hand in hand with
Poor loading, not properly distributing weight. Or bad suspension componets
It is pretty amazing what some people actually pull down the road
.

 

[Ready_fire_aim]

That makes a lot of sense!

I will add that one of the trailers I saw do this at highway speeds was totally empty. It was a large double axle car hauler type flat trailer.

 

[GC7]

Jokingly, it is largely caused by "I'm a man and I have a truck" syndrome which makes people think they can do anything without formal/proper knowledge and training.

 

[Bocephus123]

That makes a lot of sense!

I will add that one of the trailers I saw do this at highway speeds was totally empty. It was a large double axle car hauler type flat trailer.

some are not balanced well when built axle placement is critical!

 

[rickm]

A empty trailor will do it if you make a sudden swerve at a high rate of speed, especially if it is a lite trailor.