Guys,

I think I may have found the vibration/shuddering problem....
I'm not an expert, but this is my opinion at this point.
It's not the rear end, drive line, or clutch packings (for the higher speed vibrations). This weekend I was loading stuff in the bed and accidently dropped the tailgate very slightly. To my amazement the bed kept vibrating and shuddering for 2-3 seconds. I did it again, and again and it was the same feeling I feel at the higher speeds. If you take your tail gate and drop it only 1 inch inch, you'll see the bed vibrate excessively. In fact if you do it and put your hand on the edge of the bed, you can feel the vibration travel to the front of the truck and then to the rear, back and forth till it goes away. I tried this on the neighbors older truck to see if it was normal...clearly not. I had the girlfriend do this and then sat in the drivers seat...same feeling I feel at higher speeds. It's like a vibration through the frame which causes the box to shake.
I think at the right speed the vibration is accentuated. I've always thought it strange that the truck would rattle and shudder over light bumps, well after the initial bump was felt. I've watched the bed and tailgate while this happens and thought it was something loose or a bad tire...it's not. I've got the dealership looking into this now and will let you know what I find out. They have coined the phrase "tailgate test" on other trucks as well.
Could be a simple fix and I hope so as everything else I love about the truck except this incessent shuddering vibration at higher speeds...and lower for that matter. I've been a Ford fan for years and look forward to helping the rest of you Ford fans to find a solution as well.

 

I have the 3.55 LS with 4000 miles.....

 

I have a 2004 F150 FX4 with 3.73 limited slip. This is my first full size truck (other than a Toyota 4Runner I owned years ago). Compared to my wife's 2001 Eddie Bauer Expedition, this vehicle has exceptional handling characteristics but I do notice that the steering wheel has allot of feedback. I do not notice significant vibration that would suggest I have the problem mentioned by so many of the users in this forum but the feedback does seem extreme. My truck was manufactured in Virginia in mid September 2003. I noticed that there are two Technical Service Bulletin posted by another user of this forum where the vibration problem is noted. One of the TSBs notes that there is steering wheel "nibble/shimmy" at speeds in excess of 60 mph on vehicles produced prior to 8/30/03 and a different one that states the same problem but no specific date.

All that said, what the heck is steering wheel "nibble/shimmy" and how would you folks explain it to someone like me who is mechanically challenged? Is it similar to the feeling of having a wheel/tire out of balance or severely worse? As I said above, I mostly notice the feedback in the steering wheel and it seems to be very sensitive (i.e. I "feel" every bump in the road).

 

thenetguy, I think your on to something. My tailgate causes the same vibration through the whole truck. I have one of those rollock toneau covers that are all aluminum slats that roll up into the front and when driving the cover slaps up and down over any slight bump, so I know the bed is bouncing around back there. This could definately be the after bump vibration we are feeling.
It is not however the driveline rumble @ 45-55 mph that I'm getting. But it is one piece of the puzzle perhaps.

 

I found this by accident but belive it's the bigger issue as well. I've confirmed this with 4 other trucks now. The low shudder is much better once they replaced the fluid with a new type however it's still there when I turn a corner on a steep hill. I don't do it to often, so I'm trying to learn to live with it, but this wobble in the truck bed is driving me nuts. The worst part is I don't see how they can fix it, but fortunately the dealership I'm dealing with had some pretty sharp Blue Oval certified suspension technicians, so I'm remaining positive and hopeful.

 

I have a 4x4 but not screw. I got a regular cab. 500 miles so far. No problems as of yet. Hopefully it stays like that!

 

Dealer called & said parts are in to fix my truck ( throttle body "SHOULD fix it").I told him got rid of the truck. He asked if I had a shake or vibration , I told him yes, but only after you put in a ring & pinoin & flashed the computer, & when I complained about the vibration, I was told it was due to the re flash, although the work order said "could not duplicate". He said they are seeing some rear end problems & are replaceing the whole rear axle complete. I asked if the "NEW" computer flash was out yet, the answer was no, we'll get you back in when we get the new flash. I said the truck has been in six times so far & my guess is that it should have been fixed the first time. He said "we can fix it this time, when do you want to come in?" I said " I'm not kidding, I got rid of the truck, traded it, it's really gone". There was very long moment silence, it was nothing less then........................PRICELESS!

 

hah, i had a vibration when i got from 40 - 46 up tell today, i spent over 1600 dollars on rebuilding my transmission..... what was the problem.....? SPARK PLUGS!

 

I agree with fordguy61mi I also have a 145 WB_ 4x2_ 3.73 LS_ 5.4 and no vibration

 

The first five or six replies were right on target, but after that, things start drifting away from the VIBRATION issue. The vibration everyone is talking about is a sustained vibration, not some momentary shimmy. You begin feeling it it in the floorboards, and it grows and grows--the whole truck will shake until you pull off the road or slow down.

The shudder with the limited slip is a different issue. The steering wheel "nibble?" is a different issue. If you've got THE VIBRATION, you know it. It is severe and engulfs the whole truck. Mine didn't appear until 7,000 miles, and it is only interrmittent. I had it in for service, and naturally, the dealer couldn't duplicate the condition. They began to take me seriously when I took the tech for a ride and had the thing shake while I was driving it.

 

I just bought my XLT Crew with the 3.73 LS. When I test drove some others my wife and I actually noticed one was not as smooth as the other. We thought it was just us and not actually the vehicle. So far, the one I bought has been great except for once or twice I have noticed a slight shake, that I thought was in the road but couldn't tell. It only has 700 miles on it...so I am nervous about it right now. It was built in 09/03 in Canada I believe?

Time will tell...thanks for all the posts though.

 

Took my FX4 SCREW in for the slow acceleration shudder. Found out that there are 2 different 3.73 LS rears. There is a 9.75 (mine) and an 8.?? I don't get any high speed noise or shudder. Just at take off. Being fixed this week.
Other than that, this truck rides so smooth at speed that it's easy to find myself doing 85-90.

 

Interesting to note that the 3.73 limitted slip is very common among the vibration problem trucks. In previous similar type threads in this forum I believe 3.73 was also mentioned by multiple owners. Have we finally found a common trait?

 

The 3.73's major problem seems to be the clutch pack and low acceleration vibration. I think the high speed whine was more common to the lower rear. 3.65? I can't remember the number right now. The 3.73's problem is an easy fix. You just have to wait for the parts to come in.

 

I've got my truck last October. On the way home I noticed the 45 to 65mph driveline vibration. My truck has 3:55 gears 5.4 XLT 6.5' bed with Mich. (French) tires. I'm now working with the DSB to get Ford to buy back the truck because their field rep called it a "normal Ford truck nothing out of the ordinary".