Thanks for the info, I got it installed. It was a little different than your details though. There are two holes in the housing that hold the blade onto it. When I fit the blade onto the base/housing the other hole didn't line up, so I assumed it was the one you mentioned, the only issue was that the spring fell right through it. So, I installed the base on the bike, then balance the bearing on the spring, pushed it through the hole, slid the o-ring over the hole to keep the spring in, then screwed on the nut. It was tricky, but it works. It seems if I tighten too much the blade won't turn easily so I had to loosen it up, and I sprayed some lubricant on it.
Thanks again!!!