can anyone tell me how you can tell when your ball joints need to be replaced without visual inspection ?

 

When you turn you wheels really hard while moving do you hear a poping noise coming from the front end? The other way is to just jack up one tire and move the tire up and down and if it gives then the ball joints are probably bad. I've heard that if grease is coming out of the rubber boots then its possible that its bad. But you shouldn't rely on these technics as they aren't going to truely be accurate.

The only true way to tell if you ball joints are bad is to put the pickle fork under them and see how much play is in them. Hanyes auotmotive book will tell you the specifics on how much play you are allowed to have.