1998 Forester steering has become sloppy

[skinnny]

With steering wheel dead centre, and car going straight ahead, I turn the wheel a full turn or so left, and when I come back to straight, the wheel is now to the left maybe 10/15 degrees.  And if I then turn a full turn to the right, and back to straight, the wheel is now to the right maybe 10/15 degrees.  I thought it might be low on steering fluid, but according to the dipstick lid thing, it's fine.  What else could be the problem?

Weirdly, I think this started happening after I got the car back from getting a rear wheel bearing changed.  The only way I can see this affecting the steering is if some stress was put on some steering component when it was up on the lift...but that's just a stab in the dark really.