http://i12.photobucket.com/albums/a2...G-SIN/3009.jpg
You see the notches each side above! That's where you knife edge bearing sits, that's all it does, held in place by the yoke, as Barry says there is play in this bit it's normal. The other bearings are inside that black main pillar, One at the top, one at the base. Just grab the above at those screw points & try moving it side by side see if there is any slop, shouldn't be. You can upgrade your knife edge with a bronze version, make sure you specify which version of the 3009 you have, these are dead easy to change over.