vibration issues

I have started to feel a little abnormal vibration in my v-drive, particularly I can hear it and feel it the most sitting in the driver seat. It only does it when I'm just in gear or reversing slowly. I figured it might be something with my prop or shaft, checked them both and they are super sturdy along with the rudder. I'm stumped, my friends had the same boat and I never heard this type of vibration. Also I think it goes away when you get up to wakeboard speed or faster. My tachometer has been really jumpy lately could this be a paddle wheel issue? Where is the paddle wheel typically on a v-drive boat?