TIL: The hole on the back of a tuner is for lubrication. : r Guitar What grease would you use to lubricate tuners on a classical guitar. I found using Petroleum Jelly (vaseline) too light. Any suggestions would be great. Music Nomad TUNE IT String Lubricant Sticky Tuners II: Sealed Units Haze Guitars So I have a fender, an epiphone, and a Yamaha. All with vintage tuners. What's the best lubricant for these tuners? They're all perfect; and don't need to be changed, althoughI have Fingerease Guitar String Lubricant Guitar Center