Hello,  Everyone has heard of the problems with Steinway Teflon
bushings.  They were a bad design that was put into production
prematurely.  There is nothing wrong with a properly designed PTFE
bearing, but this one was not designed well.  If Steinway had
(adequately) tested the bushing in the field they would have found
the problems and could have corrected them.  I would suspect that,
among other problems, they used the wrong grade of material.

Pure white Teflon is difficult to machine to the precise tolerances
required of a piano action.  It can be done but it requires a
specialist with a lot of experience in machining plastics.  They
probably also did not make suitable pins for the new bushings.

However, the main problem, as I have heard, was that they did not
consider the effect of a rigid bushing in a wooden part that expanded
and contracted with moisture.  The tried and true felt bushing has
a considerable margin for contraction of the wood before the action
stiffens unbearably.  Teflon does not.  This problem could probablyhave been solved by using a bushing with an elastic component that
would allow the wood to expand and contract without altering the
precise fit of the pin to bushing.

Best regards,
Spencer Chase