Ok, so I've asked several different people and got several different answers so maybe you guys can give me a more difinitive answer...
I have a 2006 F-150 5.4LV8. On the highway when I get to speeds around 65-85 MPH I get a lot of front end vibrations. Now I've heard it all from alignment to tires to balancing, etc. Any ideas??

 

From my own experience, I had the same with a bad shim at 65mph, which was an unbalanced tire that was brand new.

When I took the truck to a much better tire shop, they were puzzled with so many balancing weights to the inside rim, seemed the tire itself was an issue.

The better tire shop guy stated that you get a much better balance on both the inside and outside of the rim, but once the new tires were put on, there was almost no need for the weights, just a single on the inside of the rim.

I don't have the shim anymore since the new tires.

Again, just what was the problem I was having and what the problem turned out to be.

 

I have a vibration as well but I have also had the tires balanced twice. It started right after I got the tires rotated but after rotating them back to their original position, the vibration is still there.

 

I am having the exact same problem with my '06. If you can ever figure out what it is, PLEASE let me know.

 

I had a problem with cheap crappy tires the dealer put on. They were screwed up and the truck vibrated above 45 mph.

I had new Firestones put on and the problem went away.

 

it could be the tires, worn out balljoints/other components. for the heck of it, roatate both tires from the front to the back, if it goes away, most likely the tires. i got mud grapplers and lifted and my truck is like glass at 80

 

Alignment issues are generally tire wear and or pulling. Worn shocks can cause vibrations due to not absorbing the shocks of the road. Tires out of balance will usually vibrate again at twice the speed. So in this case 130-170MPH. Good luck. Is there any vibration at 1/2 the speed say 30-40, it will be less pronounced. Check the shot gun seat back for rear tires or steering wheel if the fronts. This is old school type of isolating the problem. Another thought could be the driveshaft balance. Naturally make sure the u-joints are serviceable, the driveshaft has to be put on a balancer especially for the job. Might put the truck up on blocks and check for any wobble or deflection.

 

Ok thanks! It's an '06 with 17,500 so it's not like she's had a lot of wear and tear. I did just put a 3" level kit on 2 months ago. I did have the vibrations before that so i know it's not the kit. Gonna be putting 33" Toyo MT's on here in the next few months. Probably wait til the tires are on then get an alignment. So we'll see...

 

My '06 F150 feels like you're driving on a washboard @ 55-60mph.
I've tested it extensively on many road types.
The speed range is very specific, 55-60mph.
I've got brand new Bridgestone Dueler AT's, it also bounced with the old Generals.

You can see the bounce, doesnt matter if you're looking in the mirror or directly at it.

I pull a 5th wheel camper, same thing.

The other day I had 2 pieces of drywall in the back. It didn't bounce. The drywall sloped up onto the tailgate forming a sort of air spoiler. Could this have aerodynamicly affected things ?? I know the weight of 2 pieces of drywall wouldn't have any affect if my 5th wheel doesn't.

I've been told, this is because Ford changed the rear shocks from inside the frame to the outside in-order to increase handling in corners...

I've been told, there may be a block from shipping still in place...

My Ford dealership doesn't know why, but wants to install a dampner for about $400. I've read this may or may not do it. I'm not ready to go for $400 til I know more...and even then it's not a fix, just a band-aid.

I'm ready to try new shocks.....

Any ideas, thoughts, etc....?

 

Keep in mind that increasing drive line angles will agravate existing conditions. Might have been marginal as stock but has been agravated and sounds like its going to get worse.