Upgrading Your Watch: How to Swap a 7s26 Movement with an NH36 Movement

Are you a watch enthusiast looking to breathe new life into your timepiece? Perhaps you've got a Seiko watch powered by the reliable yet basic 7s26 movement and you're eyeing an upgrade to the NH36 movement, which offers additional features and improved performance. In this guide, we'll walk you through the process of swapping out the 7s26 movement for the NH36, allowing you to enhance your watch's capabilities and functionality.

Understanding the Movements: 7s26 vs. NH36

Before diving into the replacement process, let's briefly explore the differences between the 7s26 and NH36 movements:

7s26 Movement:

• Found in many Seiko automatic watches, including popular models like the Seiko SKX007.
• Known for its durability and reliability.
• Offers basic timekeeping functionality with hours, minutes, seconds, and day/date complication.
• Lacks hacking (the seconds hand stops when the crown is pulled out) and hand-winding capabilities.

NH36 Movement:

• An upgrade over the 7s26, also manufactured by Seiko (SII).
• Retains the durability and reliability of its predecessor.
• Features hacking and hand-winding capabilities, allowing for precise time setting and manual winding.
• Equipped with a day/date complication.
• Offers compatibility with a wider range of aftermarket parts and modifications.

Tools and Materials Needed:

Before beginning the movement swap, ensure you have the following tools and materials on hand:

1. Watchmaker's screwdriver set
2. Hand puller or hand press
3. Movement holder
4. Tweezers
5. Cleaning cloth
6. NH36 movement
7. Gasket grease (optional)
8. Watch caseback opener

Step-by-Step Guide:

Now, let's proceed with the movement replacement process:

1. Prepare Your Workspace: Find a clean, well-lit area to work on your watch. Lay down a soft cloth to protect the watch and prevent any small parts from getting lost.

2. Remove the Watch Caseback: Use a suitable caseback opener tool to carefully remove the caseback of your watch, exposing the movement inside. Be cautious not to scratch the caseback or damage the gasket.

3. Secure the Movement: Gently lift the movement out of the case using tweezers and place it in a movement holder to keep it stable during the process.

4. Disconnect the Hands: Using a hand puller or hand press, carefully remove the hour, minute, and seconds hands from the current movement. Take note of their positions and orientation for reassembly.

5. Detach the Dial: If necessary, carefully detach the dial from the movement. Be extra cautious to avoid damaging the dial or any other components.

6. Unscrew the Movement: Use a suitable screwdriver to unscrew the screws holding the current movement in place within the case.

7. Install the NH36 Movement: Carefully place the NH36 movement into the watch case, ensuring proper alignment with the dial and hands. Secure it in place using the screws removed earlier.

8. Reattach the Dial and Hands: If you removed the dial, carefully reattach it to the NH36 movement. Then, using the hand press or hand puller, reinstall the hour, minute, and seconds hands, ensuring they are aligned correctly.

9. Test and Adjust: With the NH36 movement installed, test the functionality of the watch, including timekeeping, day/date changes, and winding. Make any necessary adjustments to ensure everything is working correctly.

10. Close the Caseback: Once you're satisfied with the installation and functionality, carefully replace the caseback of the watch, ensuring it is properly sealed to maintain water resistance.

Congratulations! You've successfully upgraded your watch from a 7s26 movement to an NH36 movement, unlocking additional features and functionality while retaining the reliability and durability Seiko is known for.

Final Thoughts:

Swapping out a watch movement requires patience, precision, and attention to detail. If you're not comfortable performing the replacement yourself, consider seeking assistance from a professional watchmaker to ensure the job is done correctly.

By upgrading to the NH36 movement, you've not only enhanced the performance of your watch but also opened up opportunities for further customization and personalization. Enjoy your newly upgraded timepiece and the enhanced horological experience it brings!