GWC - I've already seen this movie, and it's not a happy ending. Here's the deal: My black gear died too. There's one place that can fix it, Nisonger.com. But, turnaround is 60-90 days, and the cost is about $109 plus shipping. And forget about them selling you the $1 black plastic gear you need. They don't/won't sell any parts. The other option is to buy a new one $239 from either a SPF dealer or Finishline and you'll get it in a few days.
I know, this sucks. But, you ***may*** be able to fix yours. Depending on how bad the gear is, you may be able to unfreeze it. I did this to mine and I'll find out next week if it worked.
Basically, you have to take apart the speedo and spray a bit of penetrating
oil around the black gear. After spraying and soaking for a few days, then spray some white lithium grease into the same area. After a few days, mine loosened up and is turning again. So, when I fire up my car next week, I'll let you know if it works. I believe it will.
Good luck.
Scott, SPF#1230 / 393