TRAXXAS TRX4 Aluminium Front/Rear Gearbox Housing TRX4012 by GPM  [TRX4012]

Aluminium front and rear gearbox housings for TRX4 upgrades

The TRX4012 aluminium gearbox set from GPM is offered as a scale replacement for the TRAXXAS TRX4 chassis, aimed at improving mounting stability for front differential parts, suspension links, and the C-hub interface on crawler setups. This one-set upgrade targets structural stability rather than altering gear ratios or drivetrain architecture.

These precision-machined aluminium cases reduce flex compared with the stock plastic units, helping maintain correct link geometry under slow, technical crawling loads. Fitting requires removal of the original front and rear housings, transferring internal gears and bearings into the new cases, and reusing factory driveline components. No electronic or servo upgrades are implied.

Package details from the supplier list included fasteners: Stainless Steel Cap Head Screw 2.5x14 - 4 pcs, Stainless Steel Flat Head Screw 2.5x10 - 4 pcs, Stainless Steel Flat Head Screw 2.5x6 - 6 pcs. Use these screws to secure the gearbox halves, link mount points, and C-hub attachments as indicated.

Model builders seeking less play at front and rear diff mounts will find the TRX4012 aluminium gearbox a robust replacement; it ships with the stainless mounting screws listed and installs into the stock TRX4 layout with standard gear and bearing transfer steps.