Answer
The mass of the gear will remain the same and weight will decrease.
Work Step by Step
Mass is an intrinsic property of an object and hence will not change with position. Whereas, the weight of an object is the force by which Earth or any other planet attracts this object towards its centre. In this problem, as we climb up, we are going farther away from the centre of the Earth. As distance increases, the gravitational force between Earth and the object decreases. Therefore, the weight of the gear will decrease.