It started as a clicking noise as you backed out of the drive. Just a mild tap through the steering wheel. Sometimes it's not even there. But as the mileage builds over the next few weeks, the click gets bigger. Then it starts to morph into a thump as you go over potholes. A thump that turns into a shimmy. You jack up the front end and shake the wheels side to side--no problem. You shake them up and down. Big problem. There's a half-inch of slop on one wheel, though the other is tight. The diagnosis: You've got a bad ball joint.
NOTHING IS FOREVERFront suspension parts eventually wear out, but this sudden onset of slop in your ball joint probably means a lubrication failure. But wait! you say. My ball joints are sealed--there's no grease fitting to pump fresh lubricant into. They're Lubed For Life, like it says right here in the owner's manual.
You've just discovered the true life span of a permanently lubed suspension joint. The lubrication finally dries out, water intrudes inside the boot covering the moving parts, and rust and abrasive road dirt turn a ball joint or tie rod end into a loosey-goosey accident waiting to happen. Do not delay in repairing a failing ball joint or tie rod end. When it fails, the wheel involved will try to part company with your vehicle, and not quite succeed in doing so. This will precipitate two unfortunate events: loss of control at some speed, and considerable damage to the rest of the vehicle.