With wheel off ground, there is about 1/8 inch of vertical play in joint when lifted with a pry bar.
what is life of ball joints (miles) in average highway use? What is acceptable on 2006 Ford Expedition
Ford & other manufactures, stopped using greasable ball joints some time ago. Unfortunatly, now they only last about 60,000 miles. 1/8 inch play is still acceptable, 3/16 you should look to replace.