As received: the time mainspring was 3/4 inch wide by 0.0175 inch thick, and the strike mainspring was 0.0165 inch thick. There was very bad T4F pivot hole wear. The strike train had virtually no wear.
Showing front time pivot holes 3, 4, and 5 before bushing. Note excessive wear on #4
After the overhaul, (I did no bushings on the strike side), the pendulum motion was excessive, and the striking sounded sluggish. I swapped the time and strike mainsprings, and then the pendulum motion was excellent (could still have been less) and the strike sounded fine. Here are the final values of the mainspring sizes (remember that these are ORIGINAL OLD mainsprings, if they were being replaced, thinner spring should be used):
Time Spring: Original old 3/4 x 0.0165 inch
Strike Spring: Original old 3/4 x 0.0175 inch
The bottom of the clock showing date code “6091L” which means December 1906.
My job no. 4487
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