Why does my Vauxhall Astra wander left to right?

My vauxhall astra wanders from left to right on its own.I've had my wheels balanced it still does the same thing. It usually does this when I am going at around 25-30 mph. What is the problem?|||This is a general answer, I am not familiar with your car. Check that the lug nuts were properly tightened when the wheels were balanced and reinstalled. Next on the list is steering linkage ball joints and other attachment points. If it is rack and pinion steering, that assembly might have problems but that is a very expensive repair, usually. Check fluid levels for the power steering. Jack up the car and check that the wheel assembly's and bearings are in serviceable condition.





This can be very serious. I once observed a car on the freeway when the steering linkage broke a ball joint: both front wheels turned in toward the center line of the car and the car flipped end over end. No warning; one millisecond traffic was moving smoothly and the next millisecond the car was in the air doing a tumblesault.|||need and aligment or u got a sticky break most likely the left one