Thanks guys. I've got a vibration when I reach 40mph. Get worse as I go faster. Recently replaced the tires. Still same problem. I checked the bearings in all 4 wheels. They checked out fine. Its 185,000 miles. Nothing has been replaced with respect to ball joints, shocks, etc. My father seems to think its a u-joint.




Is this normal wear or could this be causing the vibration? Any suggestions as to where else I need to look.

 

Where is the vibration? Steering wheel, seat, floor where?

 

I can feel in the floor. The wheel doesn't seem to vibrate but the floor pan does.

 

In my case on my Acura I had similar symptoms from 50mph and up it show up to be bad shok apsorber. I don't know can it be at F-series.

 

I had a vibration for about 6 months. Had drive shaft checked for balance and straight cost me $40 but it ruled that out, then change u-joints in back shaft cost me $40 more still had it but I dont think they had been changed for good while. then realized shaft was moving in extension housing bushing more than it should, there will be a small amount but I could move mine about 1/4" to 3/8" in any direction so I changed bushing cost me another $30 ( ford dosent sell just the bushing only the whole extension housing at a cost of $392) most transmission shops can get bushing or u can get it from Borg warner, that got rid of about 1/2 of my vibration. Then relized pinion bearings had some movement which it should not have any got new bearing set cost me another $198 but i finally fix my vibration. I would check pinion bearings for movement and check extesion housing bushing, I could feel vibration just behind front seat and a little in sterring wheel. Hope this helps.

 

My truck is a 99 F150 super cab XLT with 5.4L and that shaft looks exactly like mine with the 5" diameter dampner on front of shaft.

 

Thanks BroncoMan. I will certainly look at those two parts and see what happens. I know I've got one heck of a vibration going. Almost to the point I don't want to drive it. Thanks