How to Inspect an American 8 Day Clock Movement


OK so you are out at a flea market, yardsale (whatever) and you come accross an old clock. What is it worth? What i always do is a quick inspection of it and that will give me an idea of how much time and or money I will have to put into it. The most important thing is the clock movement so what we are going to do is:


1. Take a look at the mainsprings, are they broke? If they are figure $10 to $15 per spring to replace plus the time it takes which could be considerable. You also want to note if they are wound up tight, if they are there is a chance that they have been setting that way for 40 years. If that is the case they may need to be replaced as they no longer have the strength/flex that they used to. I have a beautiful old Seth Thomas sitting out in the shop now in that condition. The time train works great and it chimes on the 1/4 hour (it has a seperate movement for the chimes) but it does not gong at the top of the hour because the spring has been compressed for so long. So the moral of the story is if you are going to store a clock, let the mainsprings down. Also take a look at thier condition, are there any cracks or significant rust? If so, they will probably need replacement.

2.  Next we want to check and see if all the necessary parts are there (did uncle Cal take it apart to fix it and ended up with extra parts?). The easiest and quickest way to do that is see if there is power to the stike and time trains. On an American 8 day clock movement there is a lever on the right hand side (this is part of the strike train). Make sure the mainspring is wound up some and then lift the lever. The movement should try to gong. This tells us that all the key parts are there in the strike train. If it doesn't try to gong, take a look for any obstructions (sometimes people put paper clips, hat pins in the gears I guess to stop the clock?). If there still is no movement try turning one of the top gears slightly and see if it will start freeing up the strike train. It may be that the gears are "gummed up" with oil/ dirt etc... Check each gear for damage/ wear.

3.  Now we will move on the time train. Start by locating the pendulum rod and on it will be a wire (this is called the crutch) follow it up and you will come come to the verge. The verge is a part that rocks between the teeth of a gear. This gear is known as the escape wheel and what we are looking for. Ensuring that the time mainspring is at least partially wound gently rock the crutch back and forth and hope fully the escape wheel will start turning. If it does the tells us that the time train is complete. If it does not, check for the hair pins/paper clips obstructing it. If you can not locate any obstructions put your finger on the escape wheel and apply gentle pressure as you are rocking the crutch back and forth. It may be that the gears are "gummed up" with oil/ dirt again. Check each gear for damage/ wear.

4.  OK so now hopefully you have power in both the time and strike trains and what we want to look at now is the plates. Starting with the mainspring on the strike side (S #1) inspect each of the pivot holes. What you are looking for is any excessive wear in them. This is usually easily identified as the hole will appear oval shaped instead of round as it came from the factory. As you are looking at them, gently rock the gear back and forth as the will also help identify any excessive wear. Do this for each pivot hole on the strike train and when you are done there do the same for the time train.

5. If you did locate any pivot holes that may have excessive wear they will probably require a new bushing being installed. Installing bushings is not very exspensive (if you do it your self) but do require some special tools. Taking it to a clock repair shop to have bushings installed may get exspensive?


6.  If you did note and damaged or missing gears in your inspection you will want to take into consideration the maker of the clock. As donor clock movements and parts for most of the common American clock makers are pretty common on eBay (check out our store). By common American clock makers I am speaking specifically to: Seth Thomas, Sessions, Gilbert, Ingraham, Ansonia, Welch, New Haven and Waterbury. If the clock was made by another company (i.e. Platt, Jerome etc...) you will probably have a harder time trying to locate a donor clock/part.


7.  One last note, make sure to check that the arm to hang the pendulum rod is present. Sometimes these do get removed/ knocked off.

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