vibration
 

I have recently bought a 2005 F150 STX extra cab 4.6L with 22,000 miles on it when i first drove the truck it had a slight vibration at 50-55 mph then goes away thought that it might be from sitting up for a while about a month before i bought it. It also needed new tires when i got it from dry rot have replaced tires with new all four and vibration still is there have jacked truck up to look for anything abnormal nothing is loose under truck no play in tires side to side or up and down the only other thing that i can think of would be to struts in the front you can feel the vibration on the front floor board on both sides of the truck but 22,000 miles seems a little soon for struts to be going out any input would be appreciated thanks in advance.

My 2005 STX (4.2 liter V6) had a vibration/bounce between 65 and 70; all other speeds it was fine. I had the tires balanced, rotated, and front end aligned over the course of three months to correct the problem, to no avail. I finally figured it was a bad set of tires (even though tire rotation did not move the problem).

About a month ago, I found I had a drivers side strut (shock) leaking; it had fluid all over it. Replaced both, and no more vibration/bounce.

Can't say this is your problem, as many front suspension parts can cause vibration.

There's a lot of different things that can cause that problem - although you have had the tires replaced, have them re-balance them just to eliminate that from the equation. Next thing to check is your suspension components - tie rods, idler arm, pitman arm, struts, etc. Let us know what you find.

went ahead today and had tires road force balanced with no results have been doing research on this subject and found something called a frame damper kit p/n 4L3Z-5D008-AA from ford have checked struts have not found any leaks shop that put tires on did alignment check and its ok. they said they see no reason that it is vibrating still have not found reason for problem thanks for input on this problem

Your drive shaft can be out of balance and cause vibrations. I have seen very few times it was a problem but it happens. If you can put the truck on jack stands or on a lift then just have some one run it up to 50-55 and look under see if anything is bouncing or not turning smooth. Then if it doesn't show the vibration off the ground then it has to be a bad tire or weak strut as posted before.

^^ that sounds safe :blink: