This is an 03 Expedition 4x4 that is out of warranty.

I'm getting sort of a woomp, woomp noise when I am traveling at interstate speeds, pretty much right at 70mph. If I slow down to 60 it goes away, this also causes the steering wheel to shake back and forth, not real bad, but enough to be annoying.

In addition when I am making a turn from a stop, say 90* turn, I get the feeling something is binding up, sort of like if I were in 4x4 on pavement but not quite as severe.

In neither situation am I _in_ 4x4 or A4WD. I have tried to rotate the tires but it does the same exact thing.

I'm pretty sure the two are related and I think I may know what the problem may be, but if anyone else has ideas I'd love to hear them.

Thanks,
--chad

 

Lots of things could cause this.....unbalanced driveshaft....tires out of balance....U-joints

 

Yes, they would explain the vibration at speed, but not when turning from a stop, well, maybe the U joints. Any quick way to test them?

I have the truck on the lift now, just drained the Front diff fluid, waiting for the RTV to setup. I checked the wheel bearings with the truck in the air, couldn't get anything to move by jerking around on the tire and I'm a good 200lbs. Bushings seemed to be in good shape.