Toploader Countershaft Key

I'm rebuilding a 3-speed toploader and have it partially torn down in my garage. I'm trying to remove the key that holds the countershaft in place. It is accessible through the gear oil filler hole. I drove it out at far as it feels like it can go, but it hasn't fallen out completely and the countershaft still does not move. It seems like the key is hitting something on the backside.

I seem to be forgetting or missing something obvious. Any suggestions?

-Clif

I was able to get the key out. I tapped on the countershaft to push it back in a little the opposite direction. This relieved the stress on the key and was able to tap it the rest of the way.