A gear differential is considered in the form of a mechanism with two degrees of freedom with one input and two independent outputs. The movement of each output link must adapt to the load on that link. Force adaptation ensures optimal operation of the mechanism and efficient use of energy. The definability of the motion of a gear differential can theoretically take place only if there are two inputs. The well-known automobile differential has the determinability of movement only in the state with one degree of freedom in the presence of adhesion of the wheels to the supporting surface. The absence of this connection leads to the absence of definability of motion. The differential lock provides determinability of movement, but complicates the design, reduces efficiency and makes it difficult to control. Creating an open (non-locking) definable gear differential with two independent outputs will simplify the design and increase efficiency. The article is devoted to the creation of a definable effective adaptive gear differential.