How to Replace a Window Lock Gearbox

HOW TO REPLACE A WINDOW LOCK GEARBOX

If your window handle turns but the mechanism doesn’t engage, your gearbox may be worn or broken. Replacing it restores smooth locking and secure closure.

🧰 TOOLS YOU’LL NEED

  • 🪛 Phillips screwdriver
  • 📏 Measuring tape
  • ⚙️ Replacement gearbox – Shop Gearboxes
  • 🧴 Silicone lubricant

🔧 STEP-BY-STEP GUIDE

1️⃣ Remove the Handle

Unscrew the window handle and pull it free from the spindle.

2️⃣ Remove the Lock Mechanism

Unscrew the faceplate strip and slide the mechanism out carefully from the sash.

3️⃣ Swap the Gearbox

Detach the old gearbox and replace it with your new one, ensuring it aligns with the connecting rods.

4️⃣ Refit the Mechanism

Slide the strip back into place and secure with screws.

5️⃣ Test the Operation

Fit the handle back and check that the window locks and unlocks smoothly.

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