On the current mod_cluster website there is no documentation on installing mod_cluster on a JBoss AS5 server. The documentation says that mod_cluster is distributed with the server and implies there is no additional configuration required. However, it does not include details like adding Listeners to <Server> tag and configuring the JMX MBean and dependencies.

The documentation from the mod_cluster module delivered with the JBoss AS5 points to a website that is no longer valid (http://www.jboss.org/mod_cluster/java/config.html)