JL-2, as a new version of the JL reconfigurable mobile robot system, features not only a docking and 3D posture adjusting capability between its robots, but also a multi-functional docking gripper. The basic concept of JL is that the robots in the system can simultaneously perform basic tasks in flat terrains, and in the case of rugged terrains, the robots can interconnect to enhance their locomotion capabilities. This paper introduces new designs for JL-2 by which the docking mechanism can be used as a simple gripper with 3 DOFs. Then the technologies of the docking mechanism are discussed in detail, including the workspace of the docking gripper, the docking procedure and analyses of the self-aligning ability. Then the workspaces of the posture adjusting mechanisms between two docked robots are analyzed to clarify the reconfiguration ability of JL-2. At last, a series of real experiments are proposed to test the designs and analyses and the basic performance of JL-2.