This may be a question for Rich Trethewey. Recently whenever I flush the toilet, it shuts off with a "skidding" sound much like truck air-brakes starting to fail. I thought it might be someting wearing out in the toilet fixture itself. But I then noticed that as this happens, the shower head (in the same room) vibrates along with the sound. I recall a TOH episode where a valve inside the wall of a tub/shower hook-up had worn out allowing shut-off noise detected at the sink. So my question is, before I replace this toilet with my new chair-height low-volume push-button toilet, do I need to investigate the access plumbing in the wall or floor in order to resolve the problem? What could be the source of this noise and vibration, and could a new toilet fixture be the simple answer