I have had extensive experience with Steinway Teflon bushings. These
were put out in the 1970's and caused all manner of trouble. While
I have never seen any cracking of Teflon or wood in any of these,
I can always tell that the piano has them just by playing it.
To test for Teflon bushings, I press handfuls of keys down slowly
enough to not play the strings and let them up slowly or normal speed.
If Teflon is present I will hear a "Zoop, Zoop" sound while the keys
are in motion. This is the Teflon bushings squeaking.
I have heard far more severe squeaking in some pianos. While playing,
certain keys will also rattle as the Teflon cylinders rattle in their
I have spent many hours trying to lessen this problem. These parts
designed for Teflon cannot be bushed with felt -- the hole for the
Teflon is way too big.
There is only one solution for this problem: replace the piano action
with a new one. The last time I replaced a piano action, and I do it
with Renner, our shop price was $4,250. The price is the same as if
the piano were 90 years old. If you have a chance to purchase a 1970's
Steinway, factor in the cost of a new Renner action.
The bushing I refer to here is the one inserted in the wood of the
shank-flange pivot where most pianos have felt around the brass center
pin. These Teflon canisters are also found on the wippen flange and
the jack flange in the wippen itself. The problem is extremely
maddening; there are little squeaks and rattles all though the playing
done on these pianos.
Thankfully, there were no original Steinway players using these
mistakes of the piano designers desk. However, we are often required
to add Pianomation to pianos of this vintage. When you do so without
installing a new action, the increased playing on these pianos done
by the Pianomation will cause the piano to soon sound like a squeaky
typewriter clattering away.