Um, we may need more into on this including a video so we can see what is going on. But let me give this a shot.
Check your belt in the tail and make sure it's only rotated 45*. to me, it sounds like the belt is twisted way too much. If that is not it, then start looking at the gear. But my money is on the belt. If it stays twisted too much, and it does spin, you will hear a ratchet sound, and it will kill the belt in about 5 seconds. Hope this helps. If not, shoot us a short video of what it's doing.