Heavy lubicating oil on the threads when you put the chuck on. Washer of some kind between chuck and read of spindle, preferably two thin ones then they release easily. Open chuck and put a bar across the jaws, close jaws onto bar, lock spindle & release chuck with the bar easily. Even better still, get a pair of soft jaw pump pliers and hold the shaft with Thor, they won’t marr it up and you won’t bend your locking pin. They’re really designed for holding the shaft in place, not endlessly levering against.