I have a Freelander 28QB that should be similar to the OPs unit, but mine is on a Chevy chassis so I probably cannot help.
That said, before we got this Freelander, we had a 22' 4-Winds also on a Chevy chassis.
When we developed a highway vibration, I had the tires rotated and balanced several times. Long story short, the vibration ended up being a bad drivers side front shock, as evidenced by leak marks. Even though the tires were VERY well balanced, the LF still bounced at highway speeds.
I put new Bilsteins on and that fixed it.
Tim
