Jaeger-LeCoultre Caliber 846-1 – Technical Overview from Document 1149_JLC

The Jaeger-LeCoultre Caliber 846-1 is a manual-winding mechanical movement from the 1970s, belonging to the brand’s series of compact, precise, and elegantly designed calibers. Document 1149_JLC provides a detailed technical breakdown of this specific variant, highlighting its construction, key features, and servicing instructions.

Technical Specifications

• Type: Manual-winding

• Functions: Hours, minutes, small seconds at 6 o’clock

• Jewels: 17

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

• Power Reserve: Approximately 40 hours

• Diameter: Approximately 23.3 mm

• Height: Approximately 3.9 mm

This caliber is distinguished by its compact dimensions and refined mechanical design, making it suitable for slim, classic dress watches.

Movement Features

According to document 1149_JLC, Caliber 846-1 includes:

• Small seconds subdial positioned at 6 o’clock, driven by the fourth wheel and pinion

• Efficient gear train and barrel design, optimized for steady power transmission and reduced wear

• Shock-protected balance assembly featuring a fine adjustment regulator

• Manual winding system with smooth crown action and reliable setting mechanism

The movement architecture emphasizes simplicity and robustness, allowing for ease of maintenance.

Servicing Notes

• Lubrication: Use fine oils at key points including the escape wheel pivots, balance jewels, and train wheels. Apply light grease on the barrel arbor and winding components.

• Regulation: Aim for an amplitude of approximately 270° (dial-up) with beat error under 0.7 ms.

• Small seconds mechanism: Check the seating and mesh of the fourth wheel and small seconds pinion to ensure smooth hand motion without stutter.

• Mainspring and barrel: Inspect for signs of wear or fatigue, replace if necessary to maintain power reserve.

Applications

The Caliber 846-1 was typically installed in:

• Slim Jaeger-LeCoultre dress watches from the 1970s

• Models emphasizing a classic dial layout with small seconds for a vintage look

• Stainless steel and precious metal cases, usually sized between 34 and 36 mm

• Timepieces aimed at clients valuing elegant simplicity combined with reliable mechanical performance

Conclusion

The Jaeger-LeCoultre Caliber 846-1, as detailed in document 1149_JLC, is a refined and dependable manual-winding movement designed for slim, elegant wristwatches. With its small seconds complication, high frequency, and meticulous engineering, it continues to be valued among collectors and watchmakers for its blend of tradition, precision, and serviceability.