E30 Zone

Mo odometer has stopped turnrng. Speedo works fine. Ive looked into it and aparrently there is a plastic gear that breaks up inside the cluster. Is this correct?
If so, where can i get these gears from?

Very common problem in warmer climes, but I've never come across it in the UK.
Evidence of global warming?
The gears are available from the US, but I'd confirm first that this is the problem.
As will says, a fresh instrument cluster is the simplest solution. All the cluster sub assemblies are easily removable, and can be mixed and matched.

Take it apart and have a look first, mine stopped, and when I stripped it down, the mechanism was not springing back, which meant it was working like the button was pushed in all the time.

They are pretty easy to take apart.