Speedometer - Final Drive Gears

Vehicle is 92 Passat 2.0 16v 096 auto trans. The speedometer stopped working. I took the cable out and it was OK, not broken, both end pieces OK. I then took out the plastic final drive dip stick/speedometer gear. It doesn't appear to be broken, however, when I insert it back into the final drive it spins with no resistance. My question: is it possible that the final drive gear is broken, worn? Is it made of plastic or metal? Bentley not clear on this. Or, has the small plastic gear at end of the dip stick been shaved/worn to the point that it does not engage with the large final drive gear? Anybody deal with this problem before? The small gear does not appear to be damaged. It is about a half inch in diameter. Any help will be apreciated. Thanks.
Mark