What's wrong with my XBOX 360 disk drive ?

OK, so I was playing my xbox the other day when out of nowhere I start hearing a loud and obnoxious grinding and crunching noise. I panicked and turned my console off and waited a while. After turning it back on, the noise persisted. Eventually, I couldn't even play my game. Then, when I tried putting the game in, it would make that grinding noise and say "Unreadable Disk." So after trying it a few times over, I decided to take apart the console and trouble shoot. (My warranty is up and I do not have $100 to spare for a repair.) Upon opening up the system, I saw no glaring problems with anything. I took off the metal panel from the disk drive and turned on my system to watch the disk spin and see if I could see what was wrong. But nothing. I then removed the little motor and added some more lubricant to it. still nothing. My disk drive opens and closes perfectly, there is no red ring of death..just a loud grinding noise and an "unreadable disk" message. ANY HELP ? Any way to repair it?