Spatula moves slowly

I play a Meister Hans Hoyer 801 that I've had since 1994. It's served me well over the years, and I felt it was time to replace the springs. I always felt the third valve was a little slow for whatever reason. When I disconnected the ball and socket linkage, (so it was simply the spring moving the spatula on the rod, not attached to the valve), the third valve spatula was noticeably slow. I removed the spatulas, cleaned the inside thoroughly, and lubricated the rod. The first and second valve are great, but the third valve spatula is still quite slow.

The only thing I can think of is that the hole that the rod is threaded through on this spatula is just ever so slightly too small. Does anyone have any ideas or suggestions?