Question for any luthiers and guitar techs...

There's a pretty audible creak coming from the A string on my guitar whenever I tune it. I tried putting a small amount of lubricant on the gears of the tuner but that didn't solve the problem. I'm wondering if it could be coming from the post, and if so is there anything I can do to address it? Maybe a better questions would be, SHOULD I do anything about it, or do I just let it go?