So I bought an 06 supercrew and I'm having what I'm considering a problem. The drivers side of my box seems to be loose, it moves and shakes when I'm going down the highway while the passenger side stays rock stiff. I can't see anything that looks loose and it's bothering me quite a bit. What do you guys think ?
Thanks in advance for any help !
Lewis.

 

Some of these boxes have a dampener. You may need to get one from Ford. My 2008 had one installed from the factory. I think there is an add-on solution offered from Ford, but I don't have any specific information on it. You might try a search.

 

r u seeing this in your mirror while your driving? i noticed this in my old 04 and my 06 i think its normal?

 

yes in the mirror, but it seems like it's moving too much because the passenger side doesn't seem to move 1/2 as much, also when I watch it out of my rear view mirror it rocks like mad, I'm kinda concened about this... hopefully I can get some insight !

 

Let me know if you do....Mine does the same damn thing!!

 

Mine, and 4 other people with these trucks that I know do it too. I have extended cab 6.5 foot bed and the others are 4 doors with the shorter bed.

 

My understanding is that the dampener is on the passenger side of the vehicle if it is there at all. I see a little movement as well - always have. Almost seems like sheet metal reacting to buffeting, but I know it might be more than that.

Here's the thing, though - why is it shaking to begin with? Sure there may be an issue with one side being sturdier than the other - I cannot argue for or against that with the info available. It seems to me, though, that what you are seeing is a symptom of an underlying problem, and not the problem itself. My truck has always had some choppiness to it in the back end. When these 04-08 F150s first hit the market, this board was lit up with "The Vibe" posts. A lot of us thought it had something to do with balance of the driveshaft. Others thought that crappy General tires that were prone to flat-spotting were the culprit.

Here, several years later, I still haven't changed my driveshaft. But I have changed my shocks and am running Michelin AT2s - there was definitely an improvement as changes were made. I have found that riding with weight in the back makes for a smoother ride, too - and that shouldn't surprise us. If rear springs designed to support nearly a ton (plus the truck's weight) are left unloaded, how could they not be a bit stiff and jittery, right?

If your shocks are good, if your tires are balanced (and not prone to flatspotting), and you're not judging the severity of the vibration based on how it looks on an overly bumpy road, then I really have nothing further to offer. I just wanted to give you some insight into what I've noticed after driving this truck for 6 years and 100,000 miles. I hope this helps you isolate your problem.