Removing Improper Bushings from a Seth Thomas 89D Clock Movement

In clocks, the pivots (the ends of the gear shafts) rotate in holes in the brass front plate and back plate of the movement. After years of use, these “pivot holes” wear to an oblong shape. To bring the clock back to good condition, the movement should be disassembled and cleaned. Then, the pivots are polished, each pivot hole re-centered, and a brass bushing installed to restore the hole to the correct size. Some repair shops use bad bushing techniques (such as screw-in or Rathbun bushings) to avoid taking the clock apart. 

The clock movement shown here had 16 Rathbun bushings when I received it. I removed these bushings, polished the pivots, installed proper bushings, and did the other needed repair work.

A recent customer has a Seth Thomas shelf clock with a No. 89D 8-day time and strike movement. When it stopped working, he took it to someone who repairs clocks. That repairer couldn’t make it work, and the movement looked like this when I received it:

Part of the repair process is to install bushings to remove the wear that has occurred in the pivot holes (the holes in which the ends of the gear shafts, called “pivots”, rotate). Repair shops that don’t disassemble the movement for repair may use a “Rathbun” bushing, which is a small brass plate with a pivot hole and a screw hole. Each Rathbun bushing is attached with a screw or soldered on. Rathbun bushings have no place in quality clock repair, but were commonly used years ago on American antique clocks when they weren’t worth much. Another bushing system that is even worse uses “screw-in” bushings – these should NEVER be used.

The photo above shows the 8 Rathbun bushings on the front of the movement (the small brass plates secured by the large flat head screws), and the photo below shows the 8 in back.

Notice that 2 of the Rathbun bushings are soldered on, they were probably installed many years ago. The screwed on ones may be have been recently installed.

The photo below shows Rathbun bushings (called by the alternative name Rathburn) in the 1982  clock parts and tools catalog published by S. LaRose.

Here are the Rathbun bushings after I removed them:

A proper bushing is a small brass cylinder with a hole drilled in it. Here are some examples:

Here is the front plate after cleaning and installation of 7 correct bushings:

The completed movement, front view:

Rear view (I made no attempt to remove the solder):

Top view showing the “escapement” (the part that goes tick-tock):

Conclusion

I removed the Rathbun bushings and cleaned and repaired the movement. It now runs like new and will give many more years of service.

Technical Data

Repair job 5898. Pivots polished, new pins installed in 6 pinions, 16 Rathbun bushings removed, 15 bushings installed, strike gears #1 and #2 replaced with good old ones.

This clock has its original mainsprings that are labeled ST for Seth Thomas.

  • Time mainspring: 3/4 wide by 0.0165 inch thick
  • Strike mainspring: 3/4 wide by 0.0175 inch thick
This movement was made about 1900.

See more photos.


Share this post:

Facebooktwitterpinterestlinkedin

6 comments

  1. I worked for years on time clock that went into vault doors so I do have some back ground for repairing clocks….I have retired now and learning more about repairing older clocks. right now I am rebuilding several Seth Thomas 89 movements . is there a good place to get parts , and second what is a good set of bushing to start with for these movements or do you have to order then separately?

    Thanks Roy

  2. I found a old one of these, and no nothing about clocks but want to learn how to fix it. I’m not sure what’s wrong with it, where should I start?

  3. If it is running well, it is not absolutely necessary to bush it at this time, although it might be good to have it overhauled within the next few years to avoid more wear.

  4. I have a Seth Thomas with an 89 movement. When I got the clock, it was not working so carefully removed surface dust/oil and applied a drop of 859 clock oil to all the pivot points and two drops on the teeth of the escape wheel; the clock came back to life, however, I notice the pivot points for the escape wheel and one other wheels have become oblong. If the clock is keeping good time, is it necessary to install bushings at this time or…? Thanks.

Leave a Reply

Your email address will not be published. Required fields are marked *

This site uses Akismet to reduce spam. Learn how your comment data is processed.