Mini-Z MR-02 Service Ball Differential Shaft KYOSHO MZII-003 by 3Racing  [MZII-003]

MR-02 differential shaft summary

This aftermarket ball differential shaft is intended as a spare for KYOSHO Mini-Z MR-02 micro touring platforms, covering the MM and RM variants. The MZII-003 shaft serves as the central axle within the ball differential cage and is designed for hobby electric micro touring car maintenance and repairs.

Compatibility: confirmed for Mini-Z MR-02 (MM) and Mini-Z MR-02 (RM) only, so confirm chassis type before fitting. The component locates bearings and transmits torque through the ball pack, which affects slip behavior and overall drivetrain response.

Fitting notes: remove the differential from the transmission case, carefully extract the old shaft and bearing assembly, then fit this replacement shaft with the correct orientation in the differential cage. Refit original balls and shims, verify preload and end play per the chassis manual, and use a clean bench and small hex drivers suitable for Mini-Z screws.

Tuning advice: while swapping the shaft restores mechanical reliability, differential behaviour is tuned via grease viscosity, shim arrangement, and preload. Inspect balls, shims, and grease when performing a shaft change to maintain consistent handling on carpet or smooth surfaces.