Would need the year of your vehicle, as well as make and model, in order to determine whether yours has a mechanical or an electronic speedometer. Each type of mechanism has a very different set of causes which could lead to what you're describing.
The arm makes carrying around a microscope easier.
electromagnet
If you shake it slowly nothing happens. When a wet piece of cloth is heavily shaken , the reaction makes the tiny particles of water in the fabric to jump away.(Newtons third law.) It is similar to beating a carpet, the dust jumps up
this has to do with physics, when it is cool in the air around de wood it makes the atoms get closer because of the cohesion force and that makes it sound..
It makes an electromagnet.
cable could be loose or faulty speedo..
its a 1994 cavalier the speedometer runs on its own and will not start it starts when the speedometer is not running it has the vs sensor
why would a speedometer stop working on a Mazda
rusty
It makes them self guiding.
Vibrasphere.
a fat man jumps up and dow and makes an earthquake
A blown fuse.
The cap doesn't actually crack (unless someone broke it) but bad ignition wires can cause to much resistance for the spark to travel to the spark plug so the spark jumps inside the distributor cap causing carbon tracks that resemble cracks.
It's usually the cable or the speedometer head in the dash that have problems Is it possible to lubricate the where the cable and the speedometer head cluster meet? If so, how do you get into the head or cluster?
odometer won't work w/o speedometer working
The BMW 3-Series uses the human soul as fuel, when it jumps, it's actually ripping your soul out of your body.