One wishbone......?! Always replace them in pairs, same as anything else chassis-wise. Guessing the parts were cheap if one of the ball joints has a split rubber already..?
If it's 9-3 movement it won't be your ball joints. First thing i'd be checking is wishbones/bushes, then track rods and TREs. They're easy enough to diagnose, so should know what's at fault by the time you're done.
If it's 9-3 movement it won't be your ball joints. First thing i'd be checking is wishbones/bushes, then track rods and TREs. They're easy enough to diagnose, so should know what's at fault by the time you're done.