After 140K miles,both of my Miata’s rubber shifter boots were rotten and ripped. I decided while I was replacing them, I would also perform a full shifter turret rebuild. There are many guides that document how to perform the actual rebuild, however there seems to be confusion on what parts are required. I replaced all bushings, this consists of two bushing shells, the half-moon side bushing, and the tip of shifter bushing. In addition, I replaced both wavy washers, and both rubber boots. I used the NC style inner boot and it fit perfectly.
Some of the guides show a shim washer that can also be replaced. My car contained neither shims, and I did not add them. After rebuild, the shift feel was noticeably better, less slop and more feel. This is a cheap, easy and well worth project on any Miata with a couple miles and years on it.
Official Mazda Miata Parts list for Transmission Shifter Turret Rebuild
BUSHING, SHIFTER (0398-17-462A)
INSULATOR,LEVER (M501-17-501) 2 required
WASHER,WAVE (M505-17-482) 2 required