Gears

Gears are Items dropped by Clockwork Knights, Clockwork Bishops and Clockwork Rooks. They can also be found by digging up Graves (chance of 3.07%).

Gears can be used to build an Ice Box and a Divining Rod, as well as boost the max stats of WX-78 by simply consuming them. In the Ruins, repairing Broken Clockworks with 3 Gears will spawn a friendly damaged chess monster (Damaged Bishop, Damaged Knight, or Damaged Rook).

Clockwork Knights, Clockwork Bishops, and Clockwork Rooks and their broken counterparts will not respawn, nor will graves after being dug. Therefore, Gears are a non-renewable resource in the core game.

Downloadable Content
The Reign of Giants DLC introduced renewable Tumbleweeds which have a chance of dropping Gears, also, there are significantly more Chess biomes on a map, including some with Gears simply on the ground, making Gears much easier to get.

The Shipwrecked DLC introduced Floaty Boaty Knights, which are currently the only reliable source of Gears in this DLC. Each Floaty Boaty Knight drops one to three Gears. There is also a small chance of obtaining Gears from digging Sandy Piles, using the Slot Machine, or digging up X Marks the Spot chests spawned by Message in a Bottle.

Gears can be used to craft the Quacken Drill and to restore the durability of the Iron Wind by 25%.