Was working on my car over this weekend and at one point I removed the speedo cable and gear. The tranny is only a few years old with about 14,000 miles on it. When I had new gears put in, I replaced the speedo gear on the cable with the white one. It was the closest to the correct speed. Problem is, when I removed the cable and the gear, about 2/3 of the depth of the gear has been chewed off or worn down. It does still work fine, but it has me a little concerned. Is this a normal thing to happen with not that many miles on it? Should I just leave it be or replace it and hope for the best?