Ansonia 8-Day Clock Repair: Troubleshooting Gear Binding and Endshake

Restoring an Ansonia 8-day clock often centers on correcting endshake issues where gears bind due to lack of clearance between the plates. Experts suggest that while using shims under a movement post is a reversible fix for binding, a more professional approach involves identifying if plates have been improperly flattened or if non-factory bushings were installed too deep. Restorers recommend that if a wheel lacks endshake, you should first verify that the pivots are straight and the bushings are dead flat with the plate before considering more invasive modifications.

Correcting Binding and Power Loss

If a movement is gummy and sticky, it likely hasn't run in years and requires deep cleaning. Experts suggest that if the train spins freely with a 0.010" shim but binds without it, the problem is often related to non-factory bushings that were not seated flush or are too tight on the inner diameter. Restorers recommend checking for "trauma" like bent trundles in the lantern pinions, which can indicate the arbor itself is distorted and causing the binding.

To fix bent lantern pinion trundles, specialists advise against simple straightening; it is often better to snip and replace the entire set with music wire or pivot wire to ensure uniform wear. For gear teeth, if a crack is present at the base of a tooth, experts suggest it must be cut out and a new tooth inserted rather than attempting to straighten it.

Frequently Asked Questions

1. Is using a shim to fix endshake acceptable? Restorers suggest that while shims are a reversible fix, the professional method is to track down the root cause, such as a bushing fitted too tight or an arbor that is slightly bent.

2. How do I measure required endshake? There is no universal formula, but repairers generally look for "about this much"—roughly a nice "click" of play, which can measure around 0.004" to 0.010" depending on the wheel.

3. What causes zero endshake in an original movement? Experts suggest it could be a bent plate, non-parallel plates, or a radius at the base of the pivot that hasn't been properly chamfered.

4. How can I identify non-factory bushings? Repairers suggest that factory Ansonia plates were often pressed; if a "bushing" doesn't look like a separate insert from the back of the plate, it is likely part of the original plate casting or pressing.

5. Should I replace all trundles if only one is bent? Yes, experts recommend replacing the entire set in a lantern pinion if there is any uneven wear or damage to ensure proper meshing with the wheel teeth.