Trans/Rear End Noise in my C (Video)

My C has been sitting since November or so, because it's winter and I don't use it much. I start it about once a week, every two weeks at least. Well the other day I decided I'd take it for a short ride since it hasn't been moved in so long. So I drove it around the barn, and it somehow developed a noise in the trans/rear end. I don't know why, it was fine when I parked it. It doesn't seem to be consistant. It seems like it will do it a few times, then wont do it for like 30 seconds, then will do it once, then in 30 seconds will do it five times. It's hard to hear with my cell phone video, but I'll try to take a good video of the noise with my HD camera later this week. It's obviously going to have to come apart, but I wonder if anyone has any ideas what it could be? I don't think it's trans related, because in Neutral with the clutch out, and PTO on, it doesn't make any noise. This really pisses me off, because I always make sure the trans/rear end fluid is full, and I just rebuilt the trans on my H. I was hoping to never have to look at a trans/rear end in a Farmall ever again, then this happens.

http://s664.photobucket.com/albums/vv7/faster346/?action=view&current=C1-4.mp4

Probably had some moisture in the tranny and it froze and busted the oiler gear. You need to split at the tranny and remove the top as its on the bottom shaft so ya gets to tear the tranny apaart. If you dont use the pto you dont need it anyway as it does throw the lube around to get into the valley that leads to the pto belt pulley assy.