Wheels keep turning

I have an 87 trooper with 5spd manual and 2.3 4 cylinder engine. I had the whole back end up on jackstands while replacing shoes, wheel cylinders, and drums and of course brake spring hardware. Before I got the drums on I was bleeding the brakes and I started up the truck and my wheels were turning consistantly. And now that I listened for it my transmission is making a subtle grinding noise like the clutch is slightly engaged. If I put down my clutch pedal of course the noise goes away and the wheels stop turning but I'm wondering if anyone knows why my driveshaft is turning when in nuetral. Does that sound like a pilot or throwout bearing or clutch disc problem or clutch cable adjustment?