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

MR-02 ball differential shaft overview

This replacement ball differential shaft fits KYOSHO Mini-Z MR-02 micro touring cars and is supplied as an aftermarket spare for maintenance or repair. The MZII-003 shaft functions as the rotating axle inside the ball differential cage for MM and RM MR-02 variants and is intended for hobby electric micro touring use only.

Compatibility is restricted to Mini-Z MR-02 (MM) and Mini-Z MR-02 (RM) platforms, so check your chassis code before ordering. The shaft locates the bearing stack and transmits torque through the ball differential, affecting slip characteristics and the general feel of the drivetrain.

Installation notes: separate the differential housing from the transmission case, carefully remove the worn shaft and bearing stack, then orient and install the new shaft into the differential cage. Refit the original ball bearings and shims, verify preload and end play to the values recommended in your chassis manual, and use a clean bench and small hex driver set for the Mini-Z hardware.

Tuning impact: replacing a worn shaft restores consistent engagement and helps eliminate irregular slip; significant tuning changes come from ball grease, shim spacing, and preload rather than the shaft alone. Pair the shaft swap with an inspection of balls, shims, and grease to dial predictable handling on carpet or asphalt micro tracks.