Jaeger-LeCoultre Caliber 844 – Technical Overview from Document 1147_JLC

The Jaeger-LeCoultre Caliber 844 is a manual-winding mechanical movement developed during the 1970s, designed for compact, reliable, and precise wristwatches. According to technical document 1147_JLC, this caliber features a traditional time-only layout with refined finishing and robust construction, making it suitable for elegant dress watches requiring both durability and slimness.

Technical Specifications

• Type: Manual-winding

• Functions: Hours, minutes, central seconds

• Jewels: 17

• Frequency: 21,600 vibrations per hour (3 Hz)

• Power Reserve: Approximately 40 hours

• Diameter: ~23.3 mm

• Height: ~3.9 mm

This balance of size and performance allows the Caliber 844 to fit neatly in mid-sized cases while delivering reliable mechanical precision.

Movement Features and Architecture

Document 1147_JLC details the movement’s construction with an emphasis on:

• Central seconds hand, driven by a friction spring and fourth wheel

• Robust gear train and barrel design, ensuring consistent power transmission

• Shock-protected balance assembly, equipped with a fine regulator for rate adjustment

• Compact keyless works, optimized for smooth winding and setting operations

The layout prioritizes serviceability, with a clean separation of components and easy access to critical points during maintenance.

Servicing Highlights

• Lubrication: Use fine synthetic oils at escape wheel pivots, balance jewels, and gear train bearings

• Regulation: Beat error should be minimized below 0.7 ms; optimal amplitude is 250°–280° with the watch fully wound

• Center seconds tension: The friction spring requires careful adjustment to avoid erratic seconds hand motion or slipping

• Mainspring and barrel: Check for signs of wear or fatigue, ensuring smooth torque delivery

Applications

Caliber 844 was typically fitted into:

• Classic Jaeger-LeCoultre dress watches produced in the 1970s

• Models featuring a central seconds display for clean, modern dial aesthetics

• Cases made of stainless steel or precious metals, generally sized 34–36 mm

• Watches aimed at wearers who valued precision, understated design, and mechanical craftsmanship

Conclusion

The Jaeger-LeCoultre Caliber 844, as presented in document 1147_JLC, stands as a dependable and well-crafted manual-winding movement from the brand’s 1970s portfolio. Its balance of slim dimensions, central seconds functionality, and precise engineering make it a favored caliber for vintage collectors and horologists. The caliber exemplifies JLC’s dedication to mechanical excellence and timeless design in compact form factors.