While I've seen it happed before, it's doubtful that the headset box conatned missmatched parts. That usually happens during trial installs when a few headsets are on the work bench at the same time. Evidence of prior trial or repackaging is often a sign of this possibility. But most mechanics try REALLY hard to not mix up parts like this. And if the headset was purchased on line I doubt it was ever opened before it was shipped. Even still BMX headsets don't have a big gap between their elements. Is it possible that a seal is missing? Does the function of the headset seem proper? As in spin smoothly and is able to be adjusted to have no play and still spin? Andy.