To achieve satisfying motion/force objectives, it is required for the multiarm robot manipulation to tackle unknown nonlinearities and uncertainties. Existing control schemes have a requirement that the deadzone nonlinearity in the sensor channel could be ignored. However, the sensor deadzone is widely spread in real world applications; and its existence significantly limits the robotic performances. Moreover, the kinematics and dynamics of the manipulated object cannot be accurately known as the prior knowledge. Hence, such robotic systems may not be perfectly controlled by conventional approaches. In this paper, a coordinated motion/force control method is presented to handle unknown sensor deadzone and object's uncertainty. The proposed method ensures the motion and internal force errors be bounded in a small neighborhood around the origin. Finally, comparative studies are presented to show the effectiveness and robustness of the proposed scheme.