Mugen Seiki MRX4/MRX4-R 6mm 7075 Main Shaft by 3Racing MRX4-12/TI  [MRX4-12/TI]

6mm 7075 main shaft overview

This 6mm main shaft is offered for Mugen Seiki MRX4 and MRX4-R scale touring chassis as a direct drivetrain replacement or upgrade part. It is intended for RC-scale use only and fits into the final drive train to carry spur and pinion loads while transmitting power from the gearbox to the wheels.

In practical terms the component's role is straightforward: maintain concentricity through the centerline of the drivetrain and resist wear under normal racing and practice conditions. When replacing the original main shaft, confirm alignment with bearings and mating gears, check for smooth rotation before reuse, and inspect mating surfaces for wear.

For tuning, this 7075 aluminum shaft provides a balance between stiffness and serviceability; it acts as a stable reference when adjusting gear mesh and verifying drivetrain backlash. Regular inspection for burrs, scoring, or deformation helps keep gear engagement consistent and reduces unexpected drivetrain losses.

Use this part where a direct replacement or a like-for-like upgrade is needed for MRX4/MRX4-R drivetrains; check bearing fit and gear mesh after installation and treat it as a serviceable wear item in routine maintenance.