[Merz]

I was under my car looking for rattles yesterday and noticed that my driveshaft is very loose. I can move it up and down by an inch or so by hand. Is this normal, or is my carrier bearing worn out? Im assuming it is worn out, because when i hit bumps while driving, the driveshaft rubs on the top of the exhaust heat shield and makes a terrible noise. I bent the heat shield down as just a temporary fix. If it is worn out, is there any hurry to fix it? It is $160 at subaruparts.com. Thanks alot. -Evan