Adjust a little more to accommodate the bearings. Take it until you notice that it will not yield anymore and that the bearings are very hard. Just there you become. They may not be arriving at your accommodation and that's why you have game.
Everything can be Edu. That must be seen and measured to know. But I tell you that it is quite unusual for the shaft to wear. Having no direct contact with the balls or rollers of the bearings, it is difficult to spend. Remember that the bearing is with inner and outer race.