If Bill's grease on gears test does not quiet drill.
My guess is bearings. Sealed bearings are hard to evaluate or test. The age and increase in noise with speed, indicate bearings IMO. You would have to take them out and rig up a way to spin them to hear the noise. I realize you say they are good. You say gears are good and etc. But logic says something is bad and you didn't notice. So I have to give my opinion.
Right is right, even if everyone is against it, and wrong is wrong, even if everyone is for it. - William Penn
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