Clutch? problem on 91 jetta GL

Last Thursday I was pulling off the highway onto the road that leads to the street I live on and there was a sound like a metal trash can with gravel swirling around in it. It wasn't the sound of grinding. The clutch would allow me to change gears, but there was no power being transferred to the transmission. It wasn't the same feel as a slipping clutch and as I said, it sounded like gravel swirling. The clutch only has about 15k miles on it. I'm getting ready to pull the engine & transmission to see what's wrong. Is it possible for the pressure plate or something to come loose? If so what are the symptoms? I had changed out the clutch, then changed out the engine after my sister ran it without oil. When I changed it the second time I reused the bolts with a bit of loctite. If it is the clutch, it had to have broken, not worn down. Is that even possible with normal driving?:runaround: