An ad hoc network is formed by a collection of mobile nodes without any centralized access point or existing infrastructure. Communications between mobile nodes require routing over multiple-hop wireless paths. Since mobile nodes could be of high mobility, an effective and adaptive routing protocol must have ongoing details of the topology information. However, it wastes limited bandwidth to keep routing information up-to-date and reliable. Thus, one of the crucial design objectives to achieve routing responsiveness and updating efficiency is the minimization of reaction to mobility. Specifically, a scalable and QoS-guaranteed routing protocol is desired for novel multimedia applications in mobile ad hoc networks. In this paper, we propose an efficiently repairable routing protocol, called Gravitational Cluster Routing (GCR) Protocol. It contains a stable cluster structure to cover dense areas and avoid articulation nodes. The reaction to mobility can be reduced significantly by unicast. Active routing paths can be maintained locally in each cluster. Besides, repairable levels of active routing paths, which rank their stabilities, are evaluated. By their aid, the proposed GCR can find routing paths that satisfy different parameters of QoS. These mechanisms can improve the stability of active connections.