Washer spinner is loose?

My washer recently broke you could say. I can still wash clothes, but only half the load size, other wise the washer sounds like a stampeding elephant. The spinner/rotator in the middle of the washer now jiggles side to side and spins freely if you twist it. The bottom rotator at the base (inside) the washer does not spin with it like it used to. What is wrong and how do I fix it?