Okay, I have an hypothesis.

Let's assume that some lubrication device didn't fail, and something else caused it.

Hypothetically, what would happen if the cable were very hard to turn? I can see a scenario where a cable that was too high on friction would cause a whole bunch of extra heat to build up on the teeth of the gears. Once it gets to a point where the gear starts to deteriorate, the friction only goes up and the gears just get hotter. Eventually they melt down.

What I'm getting at is perhaps a fault in the cable, the cable routing, or the speedo caused too much of a load on that gear.

Just an hypothesis.


-tp