How to Replace Watch Parts

Pry open the snap case back of the watch using a case blade. Use the palm of your hand to unscrew counterclockwise a screw-down case back. Diagnosing which watch part needs to be replaced can only be performed by disassembling the watch. Most faults are caused by dirty or unlubricated parts, according to howwatcheswork.com.

Unwind the watch by winding down the mainspring, the tightly rolled thin ribbon of steel in the mainspring barrel. Rotate the crown a few turns to identify the stopper passing over the mainspring gear. Use a toothpick while holding the crown to disengage the stopper from the gears. It will unwind. Remove the movement with a screwdriver to unscrew two screws fastening it at the edge of the case.

Place all parts separately in the parts tray. Once the watch is disassembled, fill the shot glasses with naptha to soak each part except the mainspring.

Remove the hands on the dial by placing the hands remover over the hands post. Set the hands-grabber tool on its feet on top of the dial and pull the hands from the post. Remove the dial by using a screwdriver to remove the screws from the movement.

Remove the hour wheel with tweezers and then the brass gear under the center of the dial. Remove the cannon pinion, a smaller gear on a small shaft, with needle-nose pliers. Remove the bridge that houses the mainspring and gears with a screwdriver. Remove the mainspring in the same manner. Remove the balance wheel underneath the bridge in the same manner.

Oil the jewel holes. Replace the mainspring whether it's damaged or not as a precaution. Dry the parts that were soaking in naphta. Use a jeweler̵7;s loupe to inspect them. Look for cracks, chips and bent parts. Replace damaged parts. Reassemble the watch in reverse order of its disassembly.

Set the time and wind the mechanical watch.