you should be able to push and pull to move the tires as you would the steering wheel. However, there should not be looseness. If you push and pull back and forth quickly, there should be no thunking. As you turn the wheel the steering wheel should turn and the opposite wheel should move. Push and pulling at 3 and 9 oclock is how worn steering linkage (tie rods, drag link, idler arm) is identified. You should be able to feel the looseness of worn parts can often see it too - the ball joints on the linkage will hop up and down.

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Brian Toscano