Antique Clocks/Howard/Miller Model 4899 Grandfather Clock
Recently purchased an inoperable Model 4899 Grandfather clock at a yard sale. It is a weight driven clock, however, the weights had been hung in the wrong positions. After re-hanging the weights, the clock will only run for a couple of minutes. A friend says it appears the pendulum may be too short. Do you know what the proper length is? Also, the piece at the top of the movement that appears to regulate the first gear seems to have a groove worn into the left side of the piece (facing the clock). Is this normal wear or damage caused by hanging the heavier weight on this chain?
The most common reason for clocks not to run is they need to be lubricated. Lack of oil causes high friction, also sometimes the oil will thicken and prevent the movement from operating. The first thing I would do is lubricate all the pivots and gears. I use a simple sewing machine oil for this purpose. I use a toothpick to get to the hard to oil places. Sometimes it is necessary to remove the movement to get to all the spots that need lubricating. On most floor clocks accessibility is not a problem.
If the oil has thickened and become gummy it will be necessary to remove the movement and clean it. I have found carburetor cleaner works good for this. Do this in a well ventilated area away from sources of ignition as carburetor cleaner is highly inflammable. The re-oil all the pivots and gears as described above.
Howard Miller uses a lot of Hermle movements in their clocks. These are made in Germany and are of excellent quality. If it is, in fact a Hermle, you can obtain parts from Merritts (www.merritts.comm) if you do need to replace the pallet they would probably have it.
Pendulum length should not be a factor in whether or not the clock will run. However, if it is too short it will run fast, if too long it will run too slow.
If the clock still will not run, I would listen to the beats or (ticks or tick tocks). The time interval between the beats should be equal. Some clocks use self adjusting pallets. To adjust these, allow the pendulum to make a wide swing and gradually damp down. This adjusts it. On clocks that are not self adjusting, you will have to bend the pallet arm (or verge). this can be a little tricky but it is essential to get the two beats to be equal. You can also adjust the equal beats by adjusting the clock a little out of plumb, however, this is not esthetically pleasing. It would determine if the clock is operational.
I am assuming you are referring to the escape wheel as the first gear and the pallet as the regulating device. A groove wearing in this item is generally due to lack of lubrication. The fact they had the heavier weight on the center chain would have kept the clock running longer and made the situation worse.