The answer is different for each vehicle.
Ball joints are consumable parts that need to be replaced.
Everyone drives on different terrain, with different-size tires, and has a unique way of driving into turns and braking. This all affects the life of the ball joint.
Were the ball joints greased and maintained regularly, or were they never greased?
Did you use high-quality automotive grease?
We have customers who do not grease the ball joints and bushings, and they do not last long!
We do have some customers who had 100,000 miles on a set of JBA ball joints. Not every application will have these results.
We have a 1-year warranty on the JBA ball joints because there are way too many variables that cause a ball joint to wear that are out of our control.