Gear 4

I have the weight and a gear in my inventory. I can't seem to find gear 4. And I have no idea what to do with the weight. My cursor turns blue by the gear on the top, right corner, but nothing happens. There is a key hole, but I have no key in my inventory. How do I get gear 4 and what do I do with the weight and the other gear? Help, please....

You should have a map with a hook hanging down from the top. hang the weight on that hook. You need to collect 4 gears to use on the brown gear box. you need a key to get one one of the gears; the key is in the items list in one of the maps.

Thanks. It worked!