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

Aluminum 7075 transmission housing for PROMOTO-MX

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

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 is used to reduce flex in the gearbox area and protect internal gears from impact or wear during aggressive riding or heavier motor/ESC setups, while keeping service access identical to the original layout.

For technicians and hobbyists fitting or upgrading PROMOTO-MX motorcycles, this GPM aluminum housing provides a straightforward replacement with a focus on improved gearbox rigidity; verify fit with the listed models and inspect bearing seating during reassembly.