I was working under my hood tonight and noticed something that doesn't look quite right. The passenger side of the engine compartment, towards the bottom back half, is covered in green grease. Not just a little, but ALOT. It seems to be centered around my drive shaft. I can guess that this is bad, but can someone tell me what it is and exactly how bad is it? The car drives fine, no noise or anything from down there. :?

Ya, a torn CV boots is not really noticed unless significant damage is done. The grease is a good clue as to what has happened down there.

Have a look, its an easy thing to fix, they might talk you into replacing the half axle. The mechanic gave me a credit on my half axle and knocked almost $50 dollars off my repair work. The problem being the damage may have already been done to the axle and replacing the CV boot may not be the best long term solution.

Then a good engine shampoo will clear all that grease out.

Good luck!

Yup it'* a boot alright! I would get it fixed IMMEDIATELY too as if ANY debris gets in that joint, you'll be replacing the whole shaft instead of just the boot!