I have an 18 volt cordless with a Jacoobs chuck. The chuck siezed up so I went to replace it with another Jacoobs chuck but I can not get the old chuck off of the spindle. I removed the screw inside the chuck, removed the spindle from the drill, put it in a vice, drenched it several times with PB Blaster and I cant get that thing to budge. Should I shoot and but a new one or does anyone have anymore suggestions???