The fill valve may be making the noise and vibration.
Sometimes cleaning the fill valve does it, or if not, replacement.
Hi. My home is only 4 years old. For the last few days, one of the Gerber toilets has been making a vibrating (or gurgling) sound- but it doesn't actually vibrate- it's like the water system is vibrating or something. I initially noticed this sound when the toilet tank was still filling up, and simultaneously I turned on the wash basin faucet in the same bathroom and shut off that faucet suddenly. As if the toilet tank cannot handle the sudden rush of more water available to it. I think this is worsened now, since I can always produce the sound by doing the above, but also now the sound comes every time at the END of the toilet tank filling cycle, whether or not I use the other faucet. So tried these things: I bought a new rubber flapper (the kind where you can rotate and adjust amount of water) and installed it. I wiped off the flapper seat, and it seems ok to me. Then I tried to change the amount of water going into the tank, by opening up the water valve outside the tank near the bathroom floor. Turned out this valve was less than half open. But when I open it all the way, the sound becomes bigger and continuous- perhaps again pointing to the inability of the tank to handle large amount of water coming in? Can anyone please advise what I should try next? Thanks in advance.
Thanks Terry, for such a quick reply. I'll clean/replace the fill valve as you suggest. I am completely new to any plumbing, but I'll give it a shot.