This problem wasn't mentioned previously. I wasn't hearing any bearing or gear breakdown noise, so I removed the pulsator. I found that the metal center piece was separating from the surrounding plastic support, as it would twist when pressure was applied. It was a very easy repair after watching the online video. I strongly recommend ordering a cap replacement as I did, because it is easily broken during removal. It was wonderful to see that the replacement pulsator comes with a new bolt, complete with thread seal.