I have a Panasonic Cordless Drill/Driver where the one jaw of the chuck
is out of sync with the other two. I suspect that there is a spiral
controlling the closure and that the errant jaw has jumped the thread.

With the help of a video on YouTube I have managed to remove the chuck
but it appears to be a sealed unit. Does anyone have experience of this
type and is there any alternative to just replacing it with a new one?

Andrew