OK--the bigger Penn SS reels--6500 to 8500---have two switches for the anti-reverse. The one on the top of the body, at the rear of the reel, engages or disengages the anti-reverse itself. Flipping that switch in one direction will make the handle turn backwards, and in the other one, prevent the handle from turning backwards.
There's another switch, on the bottom of the reel, towards the front, that engages or disengages a clicker. I guess when Penn first designed the reel, they decided to make the clicker feature available for people who wanted to hear that "click, click, click" that older spinning reels make
Turn the rear lever so that the handle doesn't turn backwards. If it makes the clicking noise, reach under the front of the reel and turn the switch there in the opposite direction and the clicking should go away.
Threaded Mode