My Moen shower is leaking so I need to replace the cartridge. In order to remove the cartridge (hex nut in foreground), the large round nut in back with two flat sides needs to be removed first. The problem is that I can't get a wrench around this nut. The opening of the escutchon ring is 2-1/8 inch inside diameter while the round nut is 1-3/4 inches. That leaves just 3/16 inch on each side. The nut is also sunk into the wall 1-3/8 inches deep.
Is there a special tool for this or some method of removing the round nut?
Is there a special tool for this or some method of removing the round nut?