The origin of the whammy bar dates back to the 1940s when Paul Bigsby invented his vibrato bar for the electric guitar. The Bigsby vibrato is mounted to the tailpiece of the guitar. It produces a vibrato effect and a slight variation of pitch. The contemporary whammy bar was created by Leo Fender and fine tuned by Floyd Rose. Fender combined the vibrato bar with springs, similar to pedal steel guitars, to raise and lower the pitch of the strings. The spring tension allows the bridge to move and this gives the whammy bar more variability. It is possible to accurately raise or lower the pitch of single notes or all six strings at the same time.
Loosen the whammy bar by turning it in a counterclockwise motion. Whammy bars are screwed into a hole in the bridge. They are designed for easy installation and removal. It is usually necessary to remove the whammy bar in order for the guitar to fit in the guitar case. Tighten the bar by rotating it in clockwise direction and loosen by turning it in a counterclockwise motion. Adjust the whammy bar to fit your playing style.
Remove the panel on the back of the guitar. The floating bridge and tremolo system utilises springs that allow the bridge to move back on forth. The springs are easily accessible by removing the cover plate on the back of the guitar. The panel is held is secured to the guitar with six Phillips head screws.
Adjust the tension of the springs. There are two screws that allow you to loosen or tighten the springs. Loosening the tension of the springs tips the bridge forward. This makes it easier to bend the whammy bar upwards which raises the pitch of the note but, at the same time, there is less room to bend the whammy bar downwards to lower the pitch. Consider your style and the effects that you want to achieve with the whammy bar. For example, Eddie Van Halen's dive bomb effect is produced by pushing the whammy bar down in aggressive fashion. Adjust the spring tension to fit your style of playing.
Put the back panel on. Plug the guitar in the amp and test out the whammy bar modifications.