A banging noise? The only thing that I could guess is you have over sized tires on your vehicle which is rubbing on your fender as you turn (check to see if your tire is stripping).. Now if it's a loud 'clicking' noise then that's your tranny.
I think you should also check the level of power steering fluid.
Hey harry, how are you? I suppose checking the PS fluid couldn't hurt.. I've only experienced screaming and steering wheel jerking when the fluid begins to drop but who knows, it just may 'bang'.. if it drops low enough.. Thanks for the input.