I've got a serious problem and could really use some insight, because at this point I've given up hope on my local Ford dealer (or I should say that they've thrown their hands up in frustration) and I'm not getting any resolution. I've got an 04 Super Crew with the 4.6L motor. Not long after purchasing it I had usual vibration issues. I took it to the dealer and they replaced tires. The vibration continued and they replaced more tires. The vibration continued and was 'extremely' bad when I towed, and they started talking to me about the TSBs. First they applied the dampening, then the counterbalancing, then replaced the drive shaft, replaced more tires, then the ring and pinion changeout. Bottom line is that after all this the problem is unchanged. I put new 20" wheels on it last week with Goodyear GTs and the ride is smoother, but the vibration is unchanged. I am not sure if the issue is drivetrain related or not. At 50 mph I can set the cruise and my rear end will 'gyrate' all day. At highway speeds the vibration or gyration comes and goes with no rhyme or reason. I went to arbitration and won, but the award was terrible since I'm beyond the first year. It was going to cost me approximately $7,000.00 to get a replacement of "equal value". The arbitrator found the vehicle with manufacturer's defects and safety issues and it costs me to get rid of it. Anyhow, I'm not taking the loss as I've only had the truck 13 months, so I'm trying to work through it. I'm really wondering if I'm might be able to fix or at least lessen the problem through some different shocks. Any insight? I'm at the end of my rope and am stuck with the truck but can't get beyond the problem. I appreciate any insight that can be lent.
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Does the gyration change with speed? Only thing that comes to mind right off is maybe an axle shaft. Given that it's not consistant it sounds likely to be in the running gear. Had a similar issue in my old Dodge. At low speed (<10mph) it had a very slight wobble but as the speed increased it turned into a vibration which was cyclical.

 

jack the truck up, put it on some jackstands, and have someone run it at 50 mph. see if the vibration is there. if it is, look to see if there is a bent axle.

 

The gyration is pretty consistent at whichever speed I'm feeling it at. The interesting thing is that I feel it directly in the rear end and can see and feel my bed bounce whenever I feel it. If I hit bumps, dips, it's exagerated. This is why I feel it's a dampening problem vs. a drivetrain issue. I'm no engineer, or mechanic for that matter.

 

I had a problem with the emergency brake. There is a T S B that the dealer should be aware of. Mine would come and go and at one point the truck would shutter which felt a lot worse than a vibration. After two tries the dealer fixed it. The road salt causes the emergency cable to drag. Oddly enough my problem accured in the summer. Don't know if this helps but you never know.

 

rj,

Just for grins - have you changed payload weight in your bed at all? Maybe throw in about 400-500 pounds of something in your bed and drive the truck again. Does this change the vibration?

More info is always good when troubleshooting a problem.

Also - this is not a new problem for these later year Ford trucks (2004-2006). There are plenty of threads on this site about vibration issues. Oddly enough, there does not seem to be a consistent fix. Some trucks get fixed with a new driveshaft while others get fixed with a new rack & pinion set, while others need many things replaced.

Good luck. Try to be patient. You'll get plenty of help from everyone here.

CMOS

 

Thanks for the response. I have had payloads in the bed and it did seem to help dampen out the vibration. That's yet another reason I believe it's suspension related. I have read a great deal of postings. Unfortunately they are descriptions of the problems...but not too many suggestions or fixes. Thanks-

 

Sounds like a frustrating ordeal with this truck to say the least. Here's a thought.....consider taking the truck to driveline specialist and have them check to see if there is a balance issue with the drive train from the transmission back to the rear wheels. There is a great thread on this site discussing this type of vibration issue and the specialized eqipment needed to diagnose it (eqipment most dealers don't have). Installing a new mis-matched driveline won't correct the problem from what the thread indicated. The fact that adding weight dampens the vibration, but does not eliminate the vibration leades me to this suggestion. It sounds like a drive line out of balance issue to me.

Good luck,

Shawn

 

I wonder if this has anything to do with the outboard mounted shocks? I know Ford did it for the "ride quality" but maybe it made this worse. My 06 has a slight vib at around 55-60, but then it goes away above that speed. Just some FYI, I have watched my truck bed "shake" in my rearview mirror since the day I drove it home. I'm really starting to think that with those outboard mounted shocks, it makes the rear suspension ride so much more stiffer.
Rich

 

I fully believe it's in the suspension, however, here are some variables that have to be considered that make it hard to nail down the specific problem. The vibration felt at 50mph is constant. I can set the cruise and watch the bed 'bounce' all day long. It's really, really bad if it's a cold morning, until the tires heat up. So I thought the wheels played a role too. However, having said that, I recently stuck some nice new 20" wheels with Goodyear GTs on it and nothing changed. The bounce is the same, and exagerated when cold until they warm up, just like the stock. I've considered an aftermarket shock but don't know which way to go. I'm open to suggestions.

 

If it is affected by temp it could definitely be in the shocks. The shocks are more likely to require warning up than the tires. When I take my motorcycles out on cool/cold days they take a good 10 minutes or more to actually feel like they are doing anything. A was going to mention the TSBs I've read but after reviewing your original post all of that has probably been all done.

I think replacing the shocks is just about all you have left to try. Can't recommend one over another, I still have the originals. I'm sure someone else out there can help in that area.