TRAXXAS TRX4 TRAIL CRAWLER Brass Front/Rear Gearbox Cover by GPM TRX4012AX  [TRX4012AX]

Brass gearbox cover kit

This is a scale aftermarket brass front and rear gearbox cover engineered for the TRAXXAS TRX4 Trail Crawler platform. The component is an RC-scale wave of protection for the axle housing, designed to add structural protection and improve differential stability during technical trail runs.

Key design notes from the manufacturer include an integrated oil filler hole for easier maintenance, CNC-grade tolerances aimed at accurate differential alignment, and a measured mass of 76g that contributes predictable weight to the axle assembly. The package also supplies stainless steel cap head screws 2.5x14, 4pcs for mounting.

Installation and tuning role: the covers replace the stock axle housing caps on compatible TRX4 axle cases and act as a hard point to reduce deformation under load, which can help maintain gear mesh and differential function during slow-speed crawling and rock obstacles. No real-vehicle applications are implied; this part is for 1:10 RC scale use only.

Use this brass cover when you need a durable axle cap that provides protective reinforcement, an access point for oiling, and a predictable mass change for tuning the TRX4 trail crawler's axle behavior.