What was found
THIS IS A FACTORY SEALED INSTRUMENT MFG IN 4-79. DISC POINTER HAD CIRCULAR SCRATCH WERE IT CONTACTED ONE OF THE DIAL SCREWS. IN SIMILAR ALTIMETERS, PILOTS HAVE REPORTED HANG-UPS OF UP TO 1,000 FEET, IN DESCENT, DUE TO THIS PROBLEM. ONE CRITICAL MECHANISM SHAFT HAD AN END SHAKE OF .0012 INCH, THE SPEC MIN IS .0020 INCH. A TENACIOUS BLACK DEPOSIT WAS SEEN ON TRACKING AREA OF HAND STAFF PINION. A TENACIOUS YELLOW DEPOSIT WAS SEEN ON TRACKING SURFACE OF HAIR SPRING PINION. THESE DEPOSITS APPEARED TO BE A POLISHING ROUGE. HEAVY MOLY/KOTE WAS REMOVED FROM BEARING SURFACES OF THE TOP PLATE. WHEN THIS DEPOSIT WAS REMOVED, FRICTION IN THE TOP PLATE WAS REDUCED TO ONE-SIXTH THE ORIGINAL VALUE.