Front End Vibrations can be One or a Combination of the following. There are more Reasons than listed here, however, it's a Start. Hope this helps.
Worn Wheel Bearings
Worn King Pin Bearings
Worn out Steering Damper
Worn Tie Rod Ends
Incorrect Toe In
Misaligned Drive Shaft(s)
Worn Drive Shaft(s)
Damaged Drive Shaft(s)
Worn Transfer Case Mounts
Misaligned Transmission/Transfer Case
Recent changes in Suspension (ex. Lift)
Wheel Offset (ET) less than 40mm
Larger Tires
Tires Out of Balance
Uneven Tire Wear
Warped Rotors
Worn Pinion Bearings
Worn Transfer Case Bearings
Differential or Transfer Case Flange(s) Out of Round