I have 06 2500 5.9 cummins. Yesterday i noticed my steering was funny. Then i took a turn. My steering wheel shutters back and forth, and feels like the power steering is having problems. when i am stopped and turn the wheel the power steering feels fine. So i don't think it is the power steering. I heard it could be the bearings, the tie roads or the track bar. Everything seems tight. Any thoughts?

 

Get under the truck and have someone else work the steering back and forth... look for the parts that are not moving immediately when changing directions. Also should check the ball joints, generally have to lift the tire off the ground to and rock the tire to feel loose ball joints.
Could be alignment, but that generally doesn't just come on overnight - I guess it depends on how fast you notice little things going south.

 

2 or 4 wheel drive?

 

4X4? Check your panhard bar. If the jint on the end is worn they can drive fine one time and later, you've got a death wobble.