Hey guys it's been a little while since I posted here, but anyway. As I'm cruising once I hit about 50mph I start getting a vibration in the peddles and floor board. It's not real bad but noticeable for sure. When I hit 70mph it's worse and the truck even sounds like it's vibrating. As soon as I let off the peddle and coast everything is golden.. Smooth.. So it seems to be a problem only under power..

A little back story
About a year ago I was getting bad vibration and loosing power. I put it in the shop and the mechanic said the filter or screen in the gas tank was clogged so he cleaned it. I went to Korea for a year so the truck sat in government storage for a year. When I got it back in March I put in back in the shop to have the front passenger side hub replaced.

I don't know if any of that has to do with the vibration I'm getting now. Any help you offer will be appreciated.

Truck
2003 F250 ext cab
7.3l
179k miles

 

If the truck is not throwing codes (even ones that do not set the dash light), perhaps the driveshaft?

 

Was thinking the same. Either that or u-joints

 

Did it set on the tires for a year? If so may have some flat spots ? What kind of tires? AT, MT

I found my vibration coming from my mud grips so I replaced tires vibration went away.

 

Possible that the source is from the tires, though would expect the vibration to continue even when there is no load / power. Per the OP's report, the vibration stops with no power and returns with power.

Can easily check out the tire aspect by having a friend act as a spotter from another vehicle.

 

Does the truck have the two piece driveshaft? I am thinking u-joints in the shaft or carrier bearing, if it is two piece shaft

 

I will assume that it is 4x4 due to the 4" lift as my 4x4 had similar symptoms under acceleration and almost disappeared when you let off. If not, disregard.

Make sure that your hubs are truly unlocking. You can check this by tuning your wheels tight in either direction and then seeing if you can turn the wheel shafts and the shaft from the transfer case to the front differential.