What an absolutely brilliant video! This has happened on two keys our nearly new grand piano, and our trusty piano tuner has fixed it but now some other notes are doing the same. I don't want to call him out every time we get sticky underlevers and so as I am pretty good with any DIY fix this video give me the know how and confidence to give it a go! Many thanks for the upload!

FINALLY! This is *almost* what I've been trying to fix on my Kimball grand. Sooo close! My problem is that when the key is hit hard, the damper sticks in the "up" position. I have removed the action, cleaned out the cavity, removed the damper, cleaned and lubricated the wire, burnished the bushing in the guide rail hole as you show here, and still the problem persists. The hangup seems to be in the wire/ bushing, rather than in the underlever itself. I suppose bending the wire is the next step? Suggestions?

Thanks for the video, well done. I was wondering, though, if you have ever used simpler tools for this kind of thing? For example, I have a damper guide rail easing tool which is very effective in opening that hole a bit. It's really just an umbrella stay with a wooden handle. Also, Protek works great on freeing up sticking center pins throughout, though minimally helpful on old Steinways' verdigris problem. Most of the time in the winter months (here in Philadelphia area) the bushing felts get dry from the low humidity in my customers' homes due typically to their use of forced air heating systems, wood stoves and the like. The felts squeak as the pins spin against them. But as I said, a little Protek really frees things up and quiets the squeaks, typically for a long time afterward.

Utterly waste of my time. Not one second devoted to removal or reinstallation of an underlever. With upstop rail in front of underlever, this is no easy task. So what is the point of this video as it shows nothing? For future reference, a few drops of CLP applied with hypo oiler would cure sluggish underlever in a few seconds.