The clock has a small mainspring that is wound every 60 seconds.
There is a set of switch contacts that look a lot like the points on an engine distributor.
As the mainspring unwinds, the contacts come closer and closer together until they touch.
When they touch, the clock gets a 12 volt pulse and a solenoid snaps the points back and rewinds the mainspring then it starts all over again.
The original owner's manual suggests that the car be taken to the dealership and have the clock serviced every two years.
The clock is removed by twisting it about 45 degrees and pulling it out.
You will have to remove the light bulb socket and the red clock wire
You will need to remove the connector on the back of the clock (a small nut) and three small screws that hold the back cover of the clock on.
Now you can blow out the clock works with some compressed air and clean the works with some good quality contact cleaner.
You may want to use a cleaner that leaves a very light lubricant on the gears. Don't use any heavy oil like 3 in 1 oil on the gears as it will collect dust and gum up the works.
The only other thing you will need to do is to clean the solenoid contacts with some contact cleaner and a points file or relay contact burnishing tool.
Then reassemble the clock and reinstall it in the dash. My clock has worked fine since I did the above procedure. The one thing you will notice is the small 'click' noise that the clock makes every 60 seconds.