<HTML>Several months I asked about bobbling hammers in a gra= nd. I discovered that the shank lenght was too long. I now have a similar problem with a D. But this time, I've rebuilt the actio= n with new Steinway parts, (new h,s,f and wipps). There are three notes that= are driving me nuts. Unless I really smack the note, the hammer doesn't wan= t to check. They boble so bad that they hit the string on the rebound. The regulation is just like the other notes, (dip, l.o.,drop, etc.). Not onl= y is key dip just like its neighbors, but when I increased key dip, it didn'= t solve the problem. There is enough damper lever clearance. I've adjusted t= he back checks to where the hammer checks almost back down on the cushion. W= hen I try to make it check earlier, it catches. I've bent the checks so that= the rake is enough to clear the hammer on the way up, but still catches it = on the way down. I've reduced spring tension to the point of almost no rise,= and I've sanded the backs of the tails. I even changed wippens on one key, = but the problem is still there. What are some other things I should look at? Wim </HTML>