Issues! HELP!

[Guy Ramsey]

I'm having mechanical issues right now and it's confusing the hell out of me. For starters it has a vibration that started happening around 65mph, now it's worked it's way down to 40mph. So something's getting worse. The other issue I'm having (which could be the root cause) is that when I set my chain tension, the left alignment tab is moving aft about 1/4 notch while the right doesn't move at all. The real confusing part is, that despite the axel moving aft, my chain tension is becoming more and more slack. I haven't pulled the chain yet to check the length on it, but I don't think the chain has more than 10k on it. The chain is getting loose enough that it's running along the chain guard on the top of the swing arm and leaving black plastic flakes all over my left pipe. I'm a bit paranoid to ride it long distances in it's condition. Any ideas? I'm tightening the rear axle bolts to 80 lb/ft as stated in my manual so I know that's not the cause...