I can't seem to find what the correct OEM speedometer gear belongs in my car. I've been leaking tranny fluid out of the connector where the speedo cable goes in for quite some time. As it turns out the plastic shaft of the gear is worn therefore the seals can do their job. When my mechanic pulled the gear and looked it up what I had was a 45 tooth gear. He found that it should be a 42 tooth gear. 
Can anybody confirm this? Everything in the car is factory original.