Tamiya has released 04 Module Spur Gear 128T For TA04 OP-593 under Spur Gears category
Tamiya #53593 - Tamiya 04 Module Gp Spur Gear 128T (For TA04) Usable with: TA04.PRO TA04 Chassis Cars (and 53405-53407, 53420-53425) Minimal friction, low opposition, high effectiveness nylon resin spur gears which contain molybdenum.