Ordering a Mason-Sullivan Clock Movement

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Ordering a Mason-Sullivan Clock Movement

Ordering a Mason-Sullivan Clock Movement is easy but it may need to be converted to the real number. If an X is at the end of the number stamped on the back plate the conversion chart is needed. If the number has no X at the end it would need to be determined who made the clock movement for M/S. This is very easy with the clock movement identification chart. Pay particular attention to Hermle units as that is what they used the most.

The number ends with an X

If at the end of the number stamped on the clock movement does indeed have the X, the Mason and Sullivan chart is needed. Convert that number to the real manufacturers number on the chart and write it down. It is best to also put that converted number inside of the clock case for future reference for ordering any components. When searching for parts or talking about the clock, use the converted number and not the original that ended with the X.

Why the converted number helps

The new number will help find keys, pendulums chains, or any other part. The old number makes us blind to all this, the converted number turns on the lights. It will enable the user to talk about the clock and replace the movement. Everything about the movement and its components will be known and help with any future questions.


Use the Mason and Sullivan conversion chart to get the real movement number and write that number down. Click the number that is by your old number on the chart. It will go to the page where the clock movement is offered and it can be ordered. Many movements come in multiple CM lengths and this only has to match both the new and old.

Matching CM lengths

It is not needed to measure the pendulum at all during this. The reason is because the numbers and the CM length tell us everything. The CM length stamped on the movement is not the actual pendulum length. The way to measure a pendulum is covered in a different section but is not required for replacing. All that is needed is to select the same CM length as the converted number dictates and it will be the correct unit. The new movement will run the same pendulum and also every other currently used component in the clock. If it is a pendulum unit it will be required to use the drop down menu and select the CM from the list when ordering.

How the new one comes

The movement that will be sent to you will have a different number but it will be the same movement. The new movement comes with the chains or cables and pulleys if it is weight driven. Ordering a Mason and Sullivan is really not Ordering a Mason and Sullivan after all but you will get the same unit brand new.

The content of this website is copyright by Clockworks and written by James Stoudenmire in year 2022

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10 days ago

i have a mason-sullivan grandfather clock of which i have lost the nut that holds the hands on the face. can you help me to replace it

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