An apparatus for use in tuning a string of a musical instrument includes a shaft which extends from a pinion gear. A sleeve is fixedly connected to the shaft and encloses an end portion of the shaft. The sleeve has an end portion which receives a string of a musical instrument. The shaft may be integrally formed as one piece with the pinion gear. A force transmitting member may be provided between an end portion of the sleeve and a housing. A retainer portion of the sleeve may extend into a recess in the shaft. A grommet may extend around the sleeve to retain the sleeve against transverse movement.