I'm new to this,
But I have a 2006 F150 4x4 Supercrew. I have a 2.5 leveling kit on it and a set of 295/70/17 grapplers.
Okay so here is my story.

I bought the truck almost 2 years ago. Put on the leveling kit and the bigger tires and no problem until about 2-3 months ago.
Took it to the shop because everytime I would turn the steering wheel all the way to go in reverse it would make a popping noise. (Got that resolved) but that is when the vibration started. The front end would vibrate at 40mph+. Took it back and they said my tie rods were bad, replaced them and still had the vibration, took it to S&S tire and had my tires balanced and rotated and still had the vibration, took it back and they told me my upper ball joints were bad so I replaced them, and I still have the vibration.
VIBRATION DOES NOT HAPPEN WHEN I APPLY BRAKES.
I'm about to head out on a very long trip and this SH*T is really stressing me out. No one knows wtf is wrong with my truck. They say it's one thing and I replace it and nothing is resolved.
If I could please have a hint of some kind of what it might be.

 

Did you get your vibration fixed?