How to Fit an ETA Quartz Chronograph Movement: Step-by-Step Watchmaking Guide

The ETA 251.262 (and its modern successor calibre 251.272) is a 27-jewel high-grade Swiss quartz chronograph movement featured in premium timepieces from Tag Heuer, Breitling, Victorinox, and Certina. When battery leakage, coil damage, or mechanical circuit failure stops this movement, a complete calibre replacement is the most cost-effective solution. Here is our professional watchmaker's step-by-step installation guide.

Essential Watchmaking Tools Required

• Bergeon 6767 spring bar tool and caseback opener (knife or screw-type).
• Movement holder sized for 13¼ ligne (30.00mm) calibres.
• Presto hand-removing tools and dial protector sheet.
• Hand-setting press with assorted nylon tips (0.80mm to 1.50mm).
• Pin vise and diagonal cutting pliers for winding stem adjustment.
• Rodico 6033 cleaning putty and synthetic silicone grease for gaskets.

Step 1: Movement Extraction & Hand Removal

Open the caseback and locate the recessed stem release detent near the crown tube. While gently pressing the release with a 1.0mm brass peg, withdraw the winding stem. Carefully invert the case onto a clean movement cushion to drop out the movement and dial assembly. Cover the dial with a polyethylene protector and use Presto levers to lift the central chronograph seconds hand, minute counter, hour, and running seconds hands perfectly perpendicular to avoid bending the delicate pinions.

Step 2: Dial Transfer & Dial Foot Screws

Loosen the eccentric dial foot locks located along the rim of the ETA 251.262 mainplate. Carefully lift the dial straight off the old movement and seat it squarely onto the replacement calibre, securing the dial foot screws with light torque to avoid distorting the dial face.

Step 3: Hand Setting & Zero-Reset Alignment

Install the hands in precise sequence: hour hand, minute hand, central chronograph seconds, and the sub-dial register hands. Crucial Watchmaker Tip: Before pressing chronograph hands, pull the crown to the second position and press pushers A and B to verify electronic zero-reset calibration. Press hands firmly at exact 12 o'clock alignment so they zero out precisely after every split timing.

Step 4: Stem Sizing & Final Gasket Lubrication

Screw the crown onto the new winding stem and measure excess stem length against the old original stem. Trim the stem using diagonal cutters, file the cut tip smooth, and secure the crown with a drop of medium-strength Loctite 222. Clean the caseback O-ring, apply a thin film of silicone grease, and reseal the case firmly.