HPI Baja Rear Gear Box Alloy Replacement BJ012 by GPM  [BJ012]

Alloy rear gearbox for HPI Baja use

The BJ012 is an aftermarket alloy rear gear box compatible with HPI Baja scale RC kits. It functions as the rear drivetrain enclosure that retains spur gears and axles and gives a rigid mounting point for the rear differential and related drive components.

This component is aimed at hobby-level replacement and service: replacing tired housings, restoring correct gear mesh, and offering a corrosion-resistant option over stock plastic parts. The alloy material increases structural rigidity under off-road conditions while remaining suited to scale drivetrain geometry.

Installation notes: the BJ012 mounts where the original rear gear box sat and uses the standard fastener locations and internal gearing layout from the HPI Baja assembly. As with any drivetrain job, clean mating surfaces, examine internal gears and bearings before reassembly, and apply threadlocker where the chassis guide suggests it.

Tuning and maintenance role: replacing the rear box can help preserve consistent gear mesh when combating drivetrain wear or after collisions. The housing swap does not change gear ratios or electronic settings, but paired with correct spur and pinion alignment it can reduce flex-related backlash under heavy throttle and rough terrain.

BJ012 provides a durable aftermarket option focused on stabilizing rear drivetrain geometry and improving long term alignment for HPI Baja platforms during setup and repairs.