a two - component bracket and drive washer combination which provides secure holding of a magnetic sensor while automatically setting an optimal air gap , wherein operation is very quick , easy and reliable and wherein the air gap setting is precisely repeated each time a magnetic sensor is replaced or re - installed . a main bracket component has an aperture and a drive wall at one end of the aperture . a sensor body is connected to the main bracket component and is allowed to touch a reluctor . a reaction bracket has a reaction wall in the aperture opposite the drive wall and is restrained from moving . a drive washer is provided with teeth having a pitch whereby as the washer is pressed between the drive and reaction walls along a transverse axis , the main bracket component is forced to move along a longitudinal axis , thereby moving the sensor body in relation to the reluctor an amount precisely equal to a desired air gap .