The battery carrier and hold-down clamp should be clean and free from corrosion before installing the battery. The carrier should be in a sound condition so it will hold the battery securely and level. Be sure there is nothing in the carrier before installing the battery. A hold-down clap and bolt are used to hold the battery securely in the carrier. The hold-down clamp and bolt help to keep the battery from being shaken in the carrier, thus reducing the life of the battery. The bolt should be tightened to specification, but not over-tightened. To protect the battery from heat from the engine, the insulator must be installed.