The quickest fix would be to replace that diverter stem. Otherwise you have to disassemble it and clean the corrosion off the stem, replace the packing, washer, and backseating washer.: I have a problem with my tub/shower faucet. It is the kind with three separate knobs;hot, cold, and a center knob for the shower head. I have no problem with turning both the hot and cold water on, but when I turn the center knob, a loud squeeling noise is heard. This is truly obnoxious. I replaced the valves one year ago and am not experiencing any leaks. Any ideas????
