Of course the steering wheel will stop turning when you get to full lock either left or right with the engine running.
To the original poster, You don't have a problem with your tractor. You just don't. Just because the steering wheel spinner is in a different position each time you grab for it is not a problem. Your the one that put the steering wheel spinner on in the first place. And you don't need it. Or maybe a better way of saying it is "what do you need it for?" Steering wheel spinners went out of fashion a long time ago. They were needed to gain leverage so you could move the steering wheel of hard to steer tractors of yesteryear with one hand that had steering boxes and linkage. But you can move the steering wheel of your modern Kubota with one finger or the palm of your hand. There is just no need for the spinner.
Experiment for everyone to try. Shut off the engine. move your steering wheel left then right, repeat a few times as the Original Poster has done. Soon you will be able to move the wheel easily round and round as many times as you feel like doing it just as the Original Poster has done. So what? Why is this a problem? Start engine, your steering will work just fine. Now as for your emblem in the middle of the steering wheel , it will never be in the same place twice over the course of a days usage. So what? Why is this a problem? Bottom line: The original poster does not have an issue with his tractor, It is NOT broken, It does not need to be returned for repair now does it?
