4WD system not working correctly in AUTO or 4WD.

What is your question?

Just bought this vehicle a month ago and had to use the 4WD today because of snow...when in AUTO it would clunk and pop and grind and also seem like it would pull one way then all of a sudden pull the other way. And in 4WD it would do the same if not worse. Wound up having to drive home very slowly in 2WD in very slippery conditions.