Some makes of tuning machines will have a small pin cast into the machine body to prevent it from spinning under full string tension.
On your next string change, loosen the nut on the top of the post and gently push the machine off the headstock. There will be one or two small posts if that is the case. If they are like the ones I've seen, it will be hard to find a dead on replacement short of contacting the Korean mfg directly to see if they make an upgraded version.
If you go that route, try to find out who distributes them in your country of residence - if at all.
Grovers, Schallers, Sperzels (who make several that use the cast pin style) and Gotoh are all quality but the same overseas mfg who makes the ones on your guitar probably make knock-offs of these makers so you might see what style you have and go from there.
John 3:16 NIV ASB KJV - doesn't matter - Truth is truth in any translation!