Documents that speak about updates to parts and service procedures tend
to be internal documents. I don't think you will be able to research
this yourself. Besides, I don't think it will be helpful for you for
the purpose that you want it, which I am guessing is to make someone
pay for your repair instead of yourself. The mere presence of an
updated part doesn't mean the bad one was defective, nor does it
obligate a company to replace it.
Here is a sample of a service bulletin: "An updated widget kit is now
available. Use it on the following models..."
It doesn't say "An updated widget kit is now available, because we
designed the first one poorly, and there is a possibility of fire if
you don't install it." I am talking about normal service and parts
documents, not recalls here.
I would have to agree with the last writer, that going to a smaller
sales/service outlet, and speaking to the parts counter person, will
afford you the personal and knowledgable attention that you are
seeking. While that person won't have documents relating to Sears, he
will know things about your appliance because all Sears appliances are
made by other manufacturers.
In your case, if you have a front load washer made by Frigidaire, then
there is an updated shock kit that is available. If you are handy with
tools, you should be able to install this yourself.