Do they really stand behind the lifetime guarantee?

My saw is so old I no longer have the paperwork. I brought it out the
other day and it would hardly cut. I don't think it's the blade; I
either had it sharpened or I replaced it not that long ago. It roars
a lot, but doesn't cut much.

If I walk into the local Sears and request a replacement, will they
waterboard me for info I don't have, or give me a new saw, per lifeime
guarantee? or...?

Your experience appreciated.