Many things can cause the steering wheel to shake when you are driving. However, the most common cause of steering wheel shaking is a bent wheel.
Many things can cause that, the simplest cause being lack of power steering fluid.
Most common cause is warped rotors.
some cars yes (like 4 drive)
Low steering fluid can cause a steering wheel to whine when turning. A worn steering belt can also cause a steering wheel to whine when a car is being turned.
ummm power steering
A bad alternator. Turning the steering wheel all the way is very demanding on the power steering which draws power from the engine and can cause the idle to dip down. A weak alternator is usually the cause for the stalling.
How is the power steering fluid level. A low level might cause more load on the motor when turning.
Check out the bearings in the steering column and the knuckles in the steering shaft
Check and see if your power steering fluid level is low.
Anytime I've ever heard a humming noise when turning the steering wheel on any vehicle,It has always been due to low power steering fluid
That is typically a wheel balance problem.