2001 xlt supercrew xlt 4x4 with about 113,000 miles on it.

I have a vibration that I can feel in the floorboards at about 65 mph. The vibration isn't always there. It was gone for a week and now the last two days it is back. The vibration is similar to when you drive on rumble strips or drive on a road a tractor left it's tire tracks in. It reminds me of the bad torque converter vibration I had in my 86 f150.

The vibration is noticeable in the floorboard only.
I do not feel any shaking in the steering wheel.
The vibration is speed dependent and does not change it's rate when I take it out of overdrive.
I checked the wheel lug nuts and they are all tight.
I have not heard any driveshaft ringing when going from reverse to drive.
I have not heard any u-joint squeaking when driving around town.
After 15 miles of highway driving, I touched both front rims and both were the same temperature as far as I could tell.

I think it might be a front right wheel bearing (seems to me that the vibration is coming from there but that's a tough call). The other thought would be a u-joint or half shaft.

Any ideas to what might be wrong?
Are there things I can do to prove something bad or to rule it out? ie; is there a way to push/pull on the driveshaft to check for a bad u-joint?

Thanks !

 

Hey I had this happen on my 98. It drove me nuts. It finally came out to be the pitman arm had loosened from the frame rail. Check that. Oh spray a bit of silicone lube on all of the body mounts. They have a problem of getting dry and causing some wierd sounds and vibs.

 

The vibration is a standard option. No matter what I did, u joints, pitman arm, front end upgrades. I still had a vibration at 100k per hour. On the forum I learned it was a standard option of the 01 super crew. Drive shaft blancing is the only option.