Shower screeching noise after diverter is lifted.

I have a Delta single-handle shower that is making a loud screeching noise shortly after lifting the diverter. Typically the noise begins a minute or two after lifting the diverter and persists for the duration of the shower. The noise can be lessened by slightly lowering the diverter, or even just jiggling the diverter.

None of the other faucets in the house make any noise. It seems to be unique to the shower and only occurs when using the shower not when using the tub.

This is a fairly recent problem and it occurred out of the blue.

Any suggestions?

It sounds like you isolated the source of the screeching to the diverter.
I would suggest replacing the bathtub diverter, whether it's a diverter spout or diverter valve built into the valve body.

hj

When mine did it it was the water coming out of the shower head. In that case, either live with it or reduce the pressure in the house.

Mine did the same thing after it got older. The cheap rubber washer in the tub divertors gets a little hard after awhile and no longer makes a good contact/seal. It vibrates. That washer may be replaceable. It may be easier to replace the spout. Not a pro...

New diverter did the trick

on your advice I replaced the diverter and presto! no more sqweal. Thanks for the help.