[Lynn Eades]

It is at the bottom(in side) the tin shield which is still bolted to your backing plate. This is a good time to make sure your back plates are tight. the holes in the back plates are slotted where they bolt to the axle(+ tin shield).
The purpose of this set up is to take any leak from the inner hub seal into that tin shield, and out through the hole to run down the back of the back plate. it is a "tell tale" hole but they do block up pretty quickly.