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

Rear gear housing tailored to HPI Baja

The BJ012 is an alloy aftermarket rear gear box developed for HPI Baja scale vehicles. It secures the spur gear and axle layup and provides a stable mount for the rear differential and associated drive parts.

Use cases include replacing worn housings, restoring proper gear mesh, and upgrading from stock plastic to a corrosion-resistant alloy option. The alloy construction raises stiffness under common off-road loads while keeping the geometry appropriate for scale RC applications.

Installation notes: this unit installs in place of the stock rear gear box and uses the same fastener points and internal gear arrangement found on HPI Baja assemblies. Standard workshop checks apply: clean mating surfaces, inspect bearings and gears before refit, and use threadlocker where advised.

Tuning and maintenance role: swapping to this alloy housing helps preserve consistent gear mesh when addressing drivetrain wear or post-crash repair. It will not change gear ratios or electronics behavior, but it can cut flex-induced backlash when combined with correct gear alignment.

BJ012 is a straightforward aftermarket replacement aimed at better structural durability and consistent rear drivetrain alignment for HPI Baja models, useful during regular maintenance and setup work.