Why does the car shake when you turn the wheel?

actually anyone can't solve that problem correctly until you explain much about the shake.but there are many kinds of shakes.

If there is a problem in CV joints you may feel a shake.

Also if there is a problem in the connecting rod you may get the same feeling.

If you hear a noise with the shake it could be a problem of lack of Power Steering oil. If your power steering oil hose broke once, you may get the same unfortunate feeling.