When I drive slowly in a turn, and especially while parking, I often feel a subtle but noticeable bump through the wheel, like there is play in some component connecting the steering wheel to the front wheels. It occurs when I accelerate slightly, or when the wheels encounter some uneven surface. Happens in reverse too. It has been going on for at least 1.5 years but is becoming more noticeable.
There is no play when just turning the wheel left or right while stationary no matter the angle, and I don't think it's ever felt above 20 MPH as it seems to require the wheels to be turned to one side by quite a large amount. It's not easy to reproduce it on demand, but it will be felt once or twice pretty much every time I park or drive off. Unlike most of my experiences with play in mechanical components, it doesn't feel like there's a "return bump" when the components move in the opposite direction again afterwards.
Which components would be the key suspects here? The car is a Mazda 6 2003.