I want to change the chuck on a B & D 4300 ... twist type chuck ... doesn't use a key.

Any ideas please

David, October 2009

Remove the screw inside the chuck to open it it usually turns anti clockwise.
place a 10mm Alan key in chuck and close it. put the drill in gear setting one then strike the end off the Alan key with a hammer swiftly once or twice and it will twist off. only strike the end off the Alan key.

trampus09, October 2009