Need help from the hivemind.

The AC unit (the outdoor part, whatever you call it) of my house is making very loud noises. I could hear it from inside. It's a loud rattle, almost a grinding noise. I took a peek into the top and couldn't see anything rubbing against the fan blade. I'm not very handy, so that's where I ran out of ideas. Kicking it only stops the noise for about half a second. Maybe the blade is loose? Like I said, it's very loud rattling/grinding noise. It's still blowing cool air, it's just too loud to run.

It's an old AC unit, not sure how old as it came with the house. Can't even tell what model it is, only that it's a 'Comfortmaker' brand. I'm sure it's due for a replacement, as it doesn't do a great job of cooling the house anymore, but I'd like to avoid that if possible since I may be moving very soon.

I wonder if the fan motor in there is self lubricating. What happens if you spray a little WD40 where the fan shaft meets the motor housing? Also, is the compressor well bolted down to the base? Level?

Are you missing any pets?