While there is no exact lifespan that can be put on sealed ball joints, they can fail as early as  in modern vehicles, and much sooner in older vehicles. Signs of a failing ball joint may start with a sudden burst sound as a result of ball joint dismantling.
The lifespan of a sealed ball joint is uncertain, but they can fail early in both modern and older vehicles. A common symptom of a failing ball joint is the sudden sound of a popping noise when it disintegrates.