As an owner of a Craftsman 21715 15" lathe, I have found the best way to
quiet it is to pull the plug on it. That will not only save your ears, but
help keep you from strangling the people at the service desk, parts dept.,
repair scheduling, and the 15 other people you have to call when it breaks.
Hopefully you got the extended service agreement. It took over 2 months to
get a bearing replaced, finally they gave up and gave me a new lathe that I
haven't had the heart to plug in. I have the 5 year service agreement so I
can wait 4 more years to plug it in, so I can have it replaced again in
warrantee.