Clinking sound from front end, car won't drive

Well before I replace the tranny I am going to have it checked out by our “transmission specialist” in town. I was told if the car won’t roll in park then it’s not the shafts but not positive. The reason I am going to the parts yard is 3 weeks ago I bought a house and 2 weeks ago had a baby so for the next few months money is going to be tight so a new transmission isn’t in the budget for a little while. It figures the transmission would go right now of all times but what can I do.