Hi. I am attempting to replace a lift and turn tub drain replacement assembly. When I screw it it goes in crooked and does not screw far enough in to be flush with the tub...perhaps i need a little more strength! ha! I have the old one out and tried to simply screw the new one back it. It looks like plumbers putty (?) was used to install the previous one. Do I need to use it for this new one? Do I need to remove old putty? HELP!! Thanks for any advice.