I'm almost done with my rebuild and my kit came with an upgraded 2-4 servo. I'm trying to take apart the old one and have run into a snag. I pulled the snap ring out and I need to get the main shaft out of the old unit to use for the new assembly. Should this just slide out of the old unit because it will not come out. It looks like it could only slide out one way and that way will not work either. Is this normal?