We just put the new gear in and it lasted about thirty seconds so now we have to buy a new on or bring the wheel chair to a wheel chair repair shop. The other problem we had was that the two 12 volt batteries would not charge. But by charging them independantly then charging them together they are ready to go. The only thing missing is the gear. We ordered a electronic computer part that can be connected to a motor and a computer. When it is connected the computer can control the motors actions. The divice isn't as user friendly as we hoped it just came with an exploded diagram of all the parts and electonic board.