Khaitan Electricals — gearbox is broken so the fan is not swinging

Gear box of my wall fan is broken. Modle name is w 43 so it is not swinging. There is no problem with motor or its speed. The problem here is that the fanis not swinging tru and fro. This wall fan is about 5years old. It is ivory white in colour and good working. I dont have complaint regarding its coil or smooth runing capability. Again the only problem is its gearbox is needed to be changed.