Tremelo bars, also known as whammy bars, are used by guitarists to manipulate the tremelo bridge. Pushing down on the bar causes the tension on the guitar strings to decrease in pitch. Some bridges also allow a guitarist to pull up on the whammy bar to increase tension on the string, thus increasing the pitch. There are two distinct methods by which a whammy bar can be installed into the bridge. Push-in whammy bars are commonly seen on Floyd Rose bridges and other bridges based on that design, such as the Ibanez Edge bridge. Screw-in whammy bars are seen most frequently on vintage style bridges, such as the ones used by Fender.
Examine the Teflon washers to make sure none are damaged. These are the white rings placed into the slots near the end of the bar. Replace any damaged washers with new ones. Each washer has a slit in the side. The washers can be pulled straight out of the slot. Push the slit of the new washer onto the slot in the whammy bar after removing the old one. It will slide into place. The washers control how tightly the whammy bar fits into the guitar. Adding extra washers will make the bar tighter. Removing washers will make the bar looser.
Insert the end of the whammy bar into the hole in the tremolo bridge. Do not press down on the bar yet. The whammy bar should naturally fall a fraction of an inch into the hole before meeting any resistance. This helps line it up properly to install it into the bridge.
Press straight down onto the bar directly above the hole in the guitar bridge. It does not take much force to do this, but it will take a noticeable effort. You will feel the bar click into place once you press down. The push-in whammy bar is now installed into the guitar.
Line up the threaded end of the whammy bar with the hole in the tremolo bridge. You need to make sure the bar is perpendicular to the surface of the bridge. The bar will not thread into the hole properly if it is not precisely lined up.
Turn the bar clockwise a few times to begin threading it into the hole. You should not press down on the bar while doing this. Stop turning the bar if you feel resistance. If you do, remove the bar and try again.
Keep turning the bar clockwise until you feel the bar stop spinning easily. Immediately stop at that point. The whammy bar is all the way in the hole at this point. You could damage the whammy bar or bridge if you try to tighten it more.
Turn the bar counter-clockwise until it is at whatever angle you can comfortably reach it while playing. The screw-in whammy bar is now installed and ready for use.
You should remove the whammy bar from the guitar when not in use. Only install it when you plan on using the tremolo bridge. Tremolo bridges actually create a vibrato effect, which is a change in note pitch, not an actual tremolo effect, which is a change in note volume. However, this incorrect terminology is traditionally used when referring to guitar hardware.
Whammy bars must be specifically made to fit a particular bridge. Whammy bars and bridges usually are not marked, which can make it difficult to determine if a bar fits into a particular bridge. If the bar does not go in easily, do not force it. This is usually an indication that the bar and bridge are not a match. You could potentially damage the whammy bar, tremolo bridge, strings, or guitar by trying to force it in place.