I found a video on line showing how to service the transmission turret on a 90 -97 Miata and it looks like something I can tackle. I called the dealer where I bought my Mazda 3, a converted - mechanics and all - GM dealership and the best the parts guy could do was e-mail me an exploded view of the transmission and ask me - me who didn't know enough to fit battery vent hoses - to pick out the parts I wanted. Is there a shop where I can call and discuss the job and have someone understand the parts I'll need? I was mostly interested in changing the gear oil in the turret, but there are boots, springs and bushings the guy replaces in the video and it seems worth doing in a 21 year old car. I'm sure this service was never done before I got the car.
The video is here: https://www.youtube.com/watch?v=biBjZhmkxZc