Hello. We had the same problem. Felt more like we were piloting a boat than a truck and trailer. Our setup is a 2000 Ford Excursion diesel and a 36 foot travel trailer. The trailer pushed the truck all over the road. Without the trailer the truck still drove like crap. We ended up finding a bunch of problems. The setup we have now works perfect. He is what we did.
Truck:
New ball joints
New tires; we got rid of one size larger "D" rated MTs and put new Michelin E rated tires of the OEM size.
Now the truck drives perfect.
Trailer:
We had been piling too much stuff (generator, bicycles, etc) on the trailer's rear bumper so now we place much more weight up front
Installed a second sway control bar
That was it. Of course we use a weight distribution hitch. The setup now drives very smooth. Happy family now.
---Robert Vaughn, Oregon.
