'01 F-250 SD XLT 7.3ℓ 4x4
While in 2WD and slow speeds, Drive over a bump and a vibe starts coming from the front end.
The ways I have found to stop the vibe is to:
Engage 4HI, stop, or hitting another bump works sometimes.
This does not happen while in 4HI.
Could this be the 4WD driveshaft...