Has anyone tried new rear axles? I know for a fact that the circular mounting face of my rear axles are out of round. I'm not an engineer, but I'm thinking of it like this: when a wheel is out of balance, you have to add weights to counteract the heavy spots in the rim or tire. Well, wouldn't this be the same with the axels? If I can find my videos, I will upload them to show you what I’m talking about. In the meantime, the picture below will give you an idea.
What are other thoughts about this possibly being a contributor to the vibration issues?