Expert: Martin Meyer - 6/9/2007

Question
Can you provide the instruction sheet for oiling a Hermle 351-020 movement?  

Answer
Hi Karen,
    I don't know of any lubrication instruction sheet specific to this (or any) Hermle movement. The book you need is the "Hermle Service Manual", and it covers many aspects of service for all Hermle movements, including specific lubrication instructions for your movement. It is written for Hermle service techs, and costs about $20. You can get it from clock materials houses such as Timesavers and Merritt's Antiques.
    If this book is more information than you want, the general principles for oiling clock movements are: A small drop of clock oil is applied to each point where the tip (pivot) of a gear shaft goes into a hole (bearing) in the front and back main plates. There are a few other points, such as the clicks, which also need oiling, and numerous places where you definitely do NOT want oil, most notably all the levers on the outside of the front plate which operate chiming and striking, and the friction clutch on the  verge arbor. It would be more information than I could go into here to explain these exceptions. A few additional important cautions: You MUST use good clock only, never any other kind of oil. You must NEVER use any spray lubricant. You must not get oil on the gears, only on the tips of their  shafts where they go into the plates. You must not use so much oil that it drips down the plates, or the oil will be drawn out of the oil sink (shallow chamfer around each pivot hole on the outside of the plate). Finally, it is not recommended that clocks with dirty and dried oil in the bearings be lubricated. In the real world, this is very often not possible because the only alternative is to overhaul or replace the entire movement, a rather pricey repair job.
    I hope this information helps some. The Hermle Service Manual is, of course, the best guide for this procedure. Thanks for your question.  Martin