When a ball joint goes bad the ball joint will make clunking noises from the front end of the vehicle.
As the ball joints on a vehicles suspension go bad and wear out the worn out ball joints become loose in the socket and rattle and knock as the suspension travels up and down over the road.
So if you're traveling down the road and you hear a clunking or rattling noise then your ball joints are likely and need replaced.
The knocking noise or clunking noise of the bad ball joints may get worse as you travel on rough roads go over speed bumps, or when turning.
Bad ball joints do need to be replaced because if you do not replace the bad ball joints they can eventually break loose and cause you to lose control of your vehicle.
When that happens it may cause you to roll your vehicle or at least send you off the road.
Never ignore the clunking or knocking noise of the ball joints when bad and get them replaced.