How do I stop my garage from sliding down the hill?

I have a full basement under my house (which is not moving) and then the garage on the side of the house without a basement under it. I think what the people did when they built the house is not put any foundation under the garage. I live on a hill and now the garage floor slab is pulling away from the house (almost 4" so far) I don't have the money to tear it down and rebuild. is there a way to fix it?