After 3 visits to dealer, I am on the verge of filing on the lemon law. At 56-58 miles per hour the back bed shakes visibly in the rear view mirror when you have to level off at that speed. If you just normally go through that speed to a higher speed it will shake briefly and smooth right off. They have changed drive shaft, balanced and rotated tires, say they have changed one tire. It is really a pain in the butt. What else could it be that is causing this.

ALSO:

My compressor on my a/c seems to be cutting on and off a lot. How often does yours cut on and off? Mine is like every 10-12 seconds and you can hear the annoying clicking sound in the cab. Is this normal?

Thanks in advance.
I should have took the advice of another poster earlier and just took it back to them and told them to keep it.

 

The a/c might need be a little low on refrigerant. As far as the bed shake, don't look in the mirror and you won't notice it shaking

 

I've heard of this issue before but I and also the person who responded to someone who asked about this problem in the past seems to think that it is not the bed. The bed is bolted to the frame with I think 4 bolts.(The commercial that shows our truck being lifted in the air from the bed supports this). I think it is the cab that is moving but you can't notice it when you are driving. If the bed is bolted securely to the frame then I don't think that it is shaking.
As for the A/C...Mine does the same thing. I believe that is normal but I could be wrong. If the compressor was on at all times it would burn up quickly. My mustang does the same thing. normal

 

Yes the bed does shake. Mine did too. Ask the dealer to put the vibration damper on the frame. That helped reduce mine. Putting the bed extender on also reduce the shake considerably. What finally put the shake out of my misery was the Undercover hard tonneau. Now she don't shake no mo. As for the A/C compressor cycling frequently you should have the dealer check the refrigerant. Many of the 04-06 F150s come from the factory undercharged (mine did) and that will cause the cycling you describe.

 

It is indeed the bed shaking. Get behind one on the road or even beside one in town.. you can see it shake.

cdees, my dealership replaced my entire drivetrain from the transfer case back and put on a set of Michelin tires to cure mine. My truck did it starting at 50, worst at 55 and smoothed out past 60.

My bed still shakes when I hit certain sections of uneven road and when it has been sitting long enough for the tires to flat spot (which doesn't take long on today's tires as heavy as these trucks are), but the constant repeatable shake at a certain speed is gone. You probably have another vibration somewhere in the drivetrain.

These trucks have a super rigid frame and extremely tall bedsides that are bolted rigidly to that frame. Just the nature of the beast that any vibration gets magnified and shows up there.

 

The bed AND the cab both shake. They are both bolted to the frame and both move independently. You just don't notice the cab shaking because you're riding in there. I'm sure the bed shakes on almost all pick-up trucks.

 

Of course they both shake.. but for guys that like to argue the fact about the extreme bed shake being all in your head... actually get out and find some on the road and see what shakes worse... the bed or the cab.

I commented to my wife back in '04 on the very first F150 I saw in town that it looked like the bed was fixing to shake off.

I've owned trucks for the last 20 years. I've never owned one that does what these new ones do.

 

At least I know it isn't in my head. I can assure you the bed IS shaking. There is no doubt about it. It makes your whole left leg shake it gets so bad between 55-58 mph. Never thought I would pay that much for a truck that has had this many problems.
WOW! The sad part is I really love the truck and it was the exact truck I wanted to get. Exact color, exact interior, everything.
Thanks for the pointers. Just called the dealer back and they said they were going to call "FORD". Gotta love it when you hear that. Sorry for the sarcasm guys it just get frustrating when they have your truck for over a week and you pick it up after being told it is fixed and it is like they have never touched it.

 

The Ford vibration engineer is the one that gave them the go ahead to replace the entire drivetrain and quit hunting for the problem.

You may be in luck yet.

 

its definetly the bed, ya the cab may shake some but I've seen what these guys are experiencing and its all the bed. Been behind a couple on the highway that were doing it and I was amazed at how bad they shook. Mine will do it every once in a while if I am on a really rough road, but its nothing any worse than what the average truck would do on that type surface.

Good luck with it, hopefully Ford will get you fixed up.

 

Except that mine begins to shake on a perfectly smooth newly paved road. I tried to find the smoothest road I could find to eliminate the x factor of a rough road. Even on this surface at 55-58 it will start to shake and wobble. I appreciate all the info that you guys are giving me.
Thanks again.

 

I saw the sides of my bed shake, flex, wave, whatever you want to call it but I've never felt vibrations, etc through the steering wheel, etc.

Typically the dreaded vibe is felt in the wheel the bed movement is pretty much normal from my readings.

When my undercover is on the bed doesn't move at all.

 

This honestly feels like it is the tires bouncing causing the bed to shake. Does this make sense? That is because it can be felt throughout the truck.
However, tires have been indexed, rotated, balanced. Who knows????

 

That's exactly how mine was.

What tires did your truck come with? The General tires that were coming on these trucks are junk and they are all aware of it.

 

They are the continental contitrac or some junk like that. I just believe in my heart of hearts if they would put a set of michelins on there the problem would be solved. Every time I mention it they jump to "FORD will only let us put on what came on it". I am sick of hearing that answer.
I mean would it not make sense to try a set of those to see and if that fixes the problem then you have saved a lot of money by not replacing parts that do not need it. That might be why vehicles cost so much these
days. QUAKRSTAKER---- what finally fixed your problem?