I have a 02 F250 V10. When I am pulling a trailer and began to travel over 50 MPH the truck feels like its moving left to right almost like its sliding on ice. Its worse the more weight I am pulling. When I am not pulling anything there is no issues. The trailers I am pulling are gooseneck trailers. What would cause this.

 

What would cause swaying? A few possibilities.

1) Under inflated tires

2) Worn out tires.

3) Worn out shocks

4) Loose steering components, tie rod ends, ball joints, etc. Needing an alignment.

 

Consider checking pin weight. Adjust pin weight to 20% of the actual trailer weight.

 

Sway bars and weight distributing hitch?

 

With a gooseneck??????

 

Forget the hitch. My truck came from the factory with a sway bar system though.

 

The truck MAY have an anti-sway system, but the trailer may still be too much for it...

all the above with low tire air and poor weight distribution with too much weight off the back of the trailer and not on the hitch...

 

I am not sure what pin weight is or how to adjust it.

 

I am pulling a 4 stall horse trailer 28 feet long. Also a 24 foot flatbed used mostly to haul hay.

 

Tires are about 40% left, and they are at correct pressure.

 

Pin weight is the weight exerted on the 5th wheel hitch. Of the total trailer weight, 20% should be on the truck's 5th wheel and the other 80% is on the trailer axles. Low pin weight will cause swaying.

 

adjust it by moving your load around....

suspect it's too light up front so move some of the load toward the front of the trailer so it pushes the rear of the truck down

also, check your trailer AND tow vehicle tire air pressure and set to the max they can hold...

worst case scenario, the hitch system is not centered...