Replacing Hermle quartz movements
Replacing Hermle Quartz movements is sort of tricky. The units are no longer made and the new ones that are available mount in a different way. The Hermle Quartz clock movements were mounted in a way that is not typical to the rest of the quartz clock movements. This has to be taken into consideration during the quartz clock movement conversion to one of these fine alternate units.
Two ways of mounting
The Hermle Quartz are secured with a nut that went through the dial side and into the movement. The new unit instead has a post sticking out of the movement that goes through the back of the dial to the front. The new unit will have a hex nut on the front dial side to keep the movement secured.
What to do
Getting new movement requires to remove the movement from the clock case and do some measuring. So the first step is to get the movement out of the clock. The second is to measure the post that the hands go on. This is measured from the black plastic base and all the way out to the end of the minute hand nut threads. With this measurement you can deduct 1/4 inch from this, and this is the length that is needed for the new one.
Get new hands
Hermle Quartz units have unique hands. The minute hand on the new unit will have a larger mounting hole. It maybe possible to enlarge this mounting hole with a needle file so it will fit the new unit. However it is best just to get the new hands with the new unit.