ETA 2671-434 Movement Click

Operating Principle

The ETA 2671 uses a bi‑directional automatic winding system, similar in principle to the larger ETA 2824‑2, essentially a smaller version. The click works with the ratchet wheel to securely lock the mainspring’s energy during non‑winding phases (i.e., when the mainspring is fully wound or the rotor is free‑spinning), preventing accidental release due to vibration or reverse shocks.

If the click is worn or its spring loses tension, automatic winding efficiency drops significantly, the winding feel becomes abnormal, or the watch cannot stay wound even with manual winding. Like the ETA 2824, the 2671‘s small ratchet click (the “千斤”) uses a relatively delicate V‑shaped design and is prone to failure under high torque – making it a known “weak spot” of this caliber.

Usage Instructions

• Automatic Winding：During normal wear, wrist motion automatically winds the movement. The 2671 uses a relatively small rotor, so insufficient wrist movement may lead to low power reserve or stoppage.

• Manual Winding：With the crown in the normal (pushed‑in) position, rotate it clockwise to manually wind.

• Failure Symptoms：A worn click causes reduced automatic winding efficiency, unusual “clicking” noise during winding, or a “slipping” feel when manually winding. If the click is completely broken, the mainspring will release as you wind it.

• Maintenance Advice：A professional movement service every 3‑5 years is recommended to inspect the click and ratchet wheel for wear.

Installation Instructions

1. Remove Automatic Module：Open the case back, remove the movement, and take off the rotor and automatic bridge.

2. Remove Old Click：Remove the old click (2671-434) and inspect its spring for deformation and its tip for wear or breakage.

3. Clean Mounting Area：Thoroughly clean the click mounting slot on the mainplate and related gears – remove old oil and debris.

4. Inspect Ratchet Wheel：Inspect the ratchet wheel teeth; replace together if worn.

5. Install New Click：Place the new click in position, ensuring its tail spring correctly engages the mainplate‘s locating slot.

6. Reinstall Automatic Bridge：Reinstall the automatic bridge and tighten the fixing screws evenly in a diagonal sequence.

7. Test Function：Manually wind the movement and rotate the rotor to check smooth engagement and absence of noise.

Important Note：The 2671 click has a delicate structure. Ensure its spring is properly seated; otherwise, automatic winding will fail. Given that this part is a known “weak spot” of the 2671, it is advisable to replace it preventively during movement service even if no obvious failure is yet apparent. Professional installation by a watchmaker is strongly recommended.

Important Notes

• Movement Confirmation This click is specifically for ETA 2671 – verify movement model before purchase.
• Known Weak Spot The 2671‘s click is a known failure point due to its delicate structure. Preventive replacement is recommended during movement service.
• Simultaneous Replacement If the click is severely worn, inspect and replace the ratchet wheel at the same time – wear is often synchronized.
• Lubrication Requirement Apply a microscopic amount of specialized watch oil to the click‑ratchet contact points – do not over‑lubricate.
• Spring Caution The click has a tiny spring – handle with care to avoid deformation or breakage.
• Professional Advice Automatic module disassembly requires expertise – professional installation by a watchmaker is recommended.

Maintenance Guide

• Inspection Period：Inspect the click spring for deformation and the tip for wear during each movement service (every 3‑5 years).

• Wear Indicators：Signs of wear include reduced automatic winding efficiency, unusual noise during winding, or a “slipping” feel when manually winding.

• Cleaning Method：Use specialized cleaning solution and ultrasonic equipment; avoid corrosive cleaners.

• Lubrication：Apply a microscopic amount of specialized watch oil (e.g., Moebius 9010) to the click contact points.

• Replacement Interval：Replace immediately if the spring is deformed or the tip is worn or broken. Given the click is a known weak spot of the 2671, preventive replacement during service is advisable.

FAQ

Q1: What is the function of the click in an ETA 2671 movement?

The click is a locking component in the 2671‘s automatic winding system. Working together with the ratchet wheel, it locks the mainspring’s energy when the spring is fully wound or the rotor is free‑spinning, preventing accidental release due to vibration or reverse shocks. If the click fails, the mainspring cannot retain its energy, leading to complete winding failure.

Q2: Why is the 2671‘s click considered a known weak spot?

The 2671‘s click uses a relatively delicate V‑shaped design, making it prone to deformation or breakage under high torque. Additionally, because the 2671 is commonly used in ladies‘ watches with a smaller rotor, its automatic winding efficiency is inherently lower, which may lead to more frequent manual winding – further stressing the click. Therefore, preventive replacement during movement service is widely recommended even if no obvious failure is yet apparent.

Q3: Can I replace the click without removing the automatic module?

No. The click is located under the automatic bridge, so you must remove the rotor and automatic bridge to access it. This requires professional watchmaking skills; professional installation by a watchmaker is strongly recommended.

Q4: What other parts should be inspected when replacing the click?

When replacing the click, it is advisable to also inspect the ratchet wheel, mainspring barrel ratchet, and the automatic train. Wear is often synchronized across these components, and a failed click may also damage the ratchet teeth.

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