To lock down the USA and Tribute Rampage Kahler Trems ...

The USA Rampage Jerry Cantrell Signature model has the Kahler® 2320 professional brass tremelo bridge.

To lock down the trem, John Toner from G&L provided this information:

The USA Rampage has a lock screw on the back edge of the trem. It is obscured by the body's recess. You have to remove the four screws that anchor down the bridge. Lift the bridge from the body. On the back end of the bridge, there is a threaded screw hole opening for an hex screw that's about 1/4" long. In the small zip-lock bag that comes with the hex wrenches, the black hex screw will be found.

Once the screw is installed, the bridge is set to a fixed position. You will not be able to raise or lower pitch with the arm. If you remove the screw, it will raise and lower pitch normally.

Don't bother calling G&L if the hex screw is lost. We do not have spare/replacement parts. We order complete trem kits from Kahler. There are only enough kits to build our orders. Any requests for replacement parts should be directed to Kahler.

The Tribute Jerry Cantrell Signature Rampage model has the Kahler® 4300 X-Trem tremolo bridge. It also has a set screw to lock down the trem, making it a fixed bridge. It also requires lifting the bridge to set. See this adjustment chart pdf file from Kahler for the details.

For more information on these Kahler tremolos, see http://www.kahlerusa.com.