Trailer Drift/ Sway and pulling to the side.

It's also VERY dangerous when yanking pups. I have seen the back pups of a 3 pup setup almost tip over after a brief sway!

 

It’s possible that you’re not looking far enough ahead and trying to correct for every little crook in the road. Try looking as far as possible down the road,so the top of the hood is barely in view.

 

I would not say possible, I would say probable. This has an analogy in Aviation. One problem student pilots have when landing is they don't look at the distance ahead of them. They start the landing flair looking at their airspeed and reacting to every minute thing and this causes the landing to be rough and sometimes even very hard. I believe @REO6205 is privy to this as well. It took me a long time to break that habit.

 

Yup, they're called PIOs...Pilot induced Oscillations. It's basically caused by fixating on something too close to the airplane while flaring for a landing. Over correcting makes it worse. Everybody does it at least once but most of them have enough sense to abandon the approach, go around and try again.



With trucks, like everyone said, look a little further down the road and don't chase your trailer. Also, an improperly set up set of doubles...heavy trailer in back, light trailer in front, will be unstable and hard to keep pointed in one direction.

 

Is there grease on the badly maintained tractors 5th wheel plate

 

X2 5th wheel plate is dry!

 

The truck or trailer responsiveness to wind gusts will depend on model, suspension, type of trailer type of load

(light loaded or empty van will feel it the most, open flatbed least. truckwise, the less aerodynamic and taller with no air suspension or cab ride will feel it more, lower, more aero, and fixed cab then spring suspension most)