I put my zerk on the bottom because 1, i had to lock the sleeve in place and 2, because all the harleys that had zerk's from the factory that i saw had them at the bottom in the general area i mounted mine. Looking at the picture now i woukd think the zerk would be better at the top so the grease didn't have to fight its way to get all the way back to the top bearing. Hopefully it pushes up before it starts pushing out.