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# How do I replace a Mason-Sullivan Clock Movement?

*   [Knowledge Base](https://www.clockworks.com)
*   Replacing a Mason-Sullivan Clock Movement

### Article sections

### Replacing a Mason-Sullivan Clock Movement

Replacing a [Mason-Sullivan Clock Movement](https://www.clockworks.com/clock-movement/mason-sullivan-clock-movement.html) only requires the most basic tools. A pair of needle nose pliers and both styles of screw drivers is usually all that is required for the swap out. The new clock movement will be the same movement you have now but brand new, so all fits the same as it did. Having a Mason and Sullivan clock movement puts the movement 40 years old. The company went out of business this long ago so it is time to swap it out. It worked night and day for 40 years with out too much complaint, the new one will do the same.

### The disguise

The Mason and Sullivan company from MA USA built and sold countless [clock movements](https://www.clockworks.com/clock-movement/hermle-clock-movement.html) and [clock kits](https://www.clockworks.com/product-category/clock-movements/mechanical-movements/mechanical-clock-kits). So many they were able to convince the makers of these units to have there name [stamped](https://www.clockworks.com/clock-movement.html) right on the movements. Not long after that they even had there own numbering system put in place instead of the makers numbering system.

### The Availability

Although they are now out of business we can still replace the clock movement. The movements were not their own anyway and the movement producers are still in business for the most part. The [German manufacturers](https://www.clockworks.com/clock-movement.html) are making the same movements as they did 40 years ago in other words. A new movement will last longer than even the very best overhaul by [the best clock maker](https://www.clockworks.com/clock-repair/mechanical-clock-movement-restoration.html). The movement would be half the price of even a cleaning on the old unit and be brand new instead.

### The Identification

The first step is to ignore any names on the clock movement and only pay attention to the numbers. Match the numbers on [the ID page](https://www.clockworks.com/clock-movement.html) to see who made it. It may or may not have a M/S number on the back plate itself on the low right. If it is a M/S numbering system it would be followed by an X at the end of the number and go straight to the conversion chart. It will say something like 3325X or similar. This is if your clock movement has the [Mason Sullivan](https://www.clockworks.com/mechanical-clock-kits.html) number system only. As explained the exclusive M/S numbers were used only in the later years. Prior to this it would have the M/S name and the real makers numbering system. If you do not have an X in the number it is most likely a [Hermle movement](https://www.clockworks.com/clock-movement/hermle-clock-movement.html) so go to that [web page](https://www.clockworks.com/clock-movement/hermle-clock-movement.html) to match it up.

### Summery

The clock movement is most likely a [Hermle](https://hermleclock.com/) movement in disguise. The new unit can ship the same business day if ordered early enough, comes [oiled](https://www.clockworks.com/product/keystone-clock-oil) already. It will have its [chains](https://www.clockworks.com/product/grandfather-grandmother-clock-chain) or [cables](https://www.clockworks.com/product/genuine-replacement-cable-for-grandfather-clocks) if its a floor clock movement, comes with instructions and support to install the unit.

_The content of this website is copyright by [Clockworks](https://www.facebook.com/ClockworksUSA) and written by [James Stoudenmire](https://www.facebook.com/james.stoudenmire) in year 2020_

Last Updated: 2 months ago in

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