: Can anyone tell me why the "plumbing" squeals in Tub Shower Combo when I turn the middle Knob to direct the water from the Tub to the shower head.
: I can divert the water about half way before it starts to squeal/screach. How do I fix this.: Larry

Larry,
I would check the shower head first. Some have very small restrictors that speed the water and increases vibration. Other causes could be a loose washer at the diverter.