If the gap concerns you, you can disassemble everything and bend the diagonal part of the arm in slightly so that the puck bottoms out. I’ve seen a couple of people machine thicker pucks to take up the slack.
FJ60s use a nylon puck to help cut down on noise. You might want to consider just gluing the top of a plastic bottle cap to your puck and see how that goes.
Definitely NOT something you need to take to a mechanic.