LAZER ZX7.5 Center Shaft Replacement (Kyosho LAW79B)  [KY-LAW79B]

This RC-scale center shaft is supplied as Kyosho part LAW79B and is specified as an aluminum center driveline component for the LAZER ZX7.5 family. The naming indicates 88/7075 aluminum as the material reference, which points to a machined aluminum shaft intended for use as a direct replacement in the ZX7.5 center driveline assembly.

The center shaft transmits torque from gearbox outputs to differentials or intermediate gears while keeping alignment through bearings and housings. When installing LAW79B, inspect bearing clearance and retention hardware for wear, confirm the shaft turns freely before final assembly, and ensure mating gears or couplers mesh without binding. Small adjustments to bearing preload and shaft seating can reduce driveline noise and improve efficiency, so adjust carefully rather than forcing components together.

Alloy grades in the 7075 family deliver a good mix of stiffness and machinability for RC drivetrain parts, but actual lifespan depends on load and maintenance. Check the shaft surface, keyways, and set-screw interfaces regularly, and replace the shaft if you find scoring, burrs, or persistent vibration that cleaning or bearing service does not cure.