Tuning peg, Breedlove six string

Q: The tuning peg for the G string on my Breedlove 6 string guitar seems to squeak and jump pitch right before and after perfect pitch. It’s actually more like a clicking sound and an uneven turn of the peg. Any thoughts? Thanks,
Robert

A: The fault is not in the tuner. Your nut slot is too tight. As you tighten or loosen the peg, the string sticks in the nut slot. When the tension exceeds the pinch of the nut slot, the string springs through, making a squeaking sound as it goes. I suppose that the slot could be widened with a nail file, and various shapes of needle files would work fine, but the proper tool is "gauged nut file," a round edge file exactly .026" wide.

Steve Mason