Theres something wrong in the drive train. I would start with the clutch system and spur gear. Sounds like the clutch bell is not driving the spur at all. or the spur is not driving the rest of the drivetrein. Turn the clutch bell with your finger. it should drive the spur. The spur should drive axles or another gear not familiar with your vehicle but all the same. Follow the drivetrein spining and at the point where the driveline quits spining that is where your problem lies. Hope this helps.