Ball joints in 1998 Ford F150 2wd

My truck failed pa state inspection for loose wheel bearing and a bad ball joint. I tightened up the wheel bearings and went ot investigate the ball joint. I have the truck up in the air and I can not find the slightest bit slop in any of the ball joints. They didn’t specify if it was right or left, simply it was a lower ball joint. Is there another way of finding a bad ball joint, other then trying to shake the wheel?

Yes. Place the floor jack under the lower control arm and jack up the truck so the tire is off the ground 4"-5". Take a 4’-5’ long pry bar or 2X4 and place one end under the tire. Now pry up on the tire and release while someone observes the ball joint. If it’s worn it’ll be seen moving up and down in it’s socket.