A/C started making rough noises today. What should I check?

I was able to get up there today when the rain let up and it's not looking as easy as I suspected it might be. There are no nests are any obstructions. The noise seems to be coming from the vibration that the fan is giving off, although it doesn't seem lose in any parts. The rod that the fan is secured to that goes into the fan motor starts to wobble and the sounds gets louder the longer it's on. Is this an indication of a bad fan motor?