PROMOTO-MX 7075 Aluminum Transmission Housing MX038A by GPM  [MX038A]

7075 aluminum gearbox shell for PROMOTO-MX

This 7075 aluminum transmission housing is an RC-scale replacement produced for LOSI Promoto-MX motorcycles. Machined from 7075 aluminum as stated in the source, the housing replaces the stock plastic unit on the listed Promoto-MX models and is intended to increase drivetrain stiffness and long-term durability.

The unit ships with a single 5x13x4 bearing to match the supplied mounting interfaces. As an aftermarket replacement, it installs in place of the stock housing using the motorcycle's existing fasteners and drivetrain components; confirm alignment and bearing seating during installation to avoid preload or misalignment on the spur and pinion engagement.

In tuning terms this part helps reduce flex around the gearbox and shields internal gears from impact or accelerated wear during aggressive running or when using higher-power motor and ESC combinations, while keeping service access identical to the original layout.

For technicians and hobbyists fitting or upgrading PROMOTO-MX motorcycles, this aluminum housing from GPM offers a straightforward replacement that prioritizes gearbox rigidity; always verify fit with the listed models and check bearing seating during reassembly.