TRAXXAS TRX4 Trail Crawler Brass Rear Knuckle Arms Inner Case by GPM TRX4022BX  [TRX4022BX]

Overview

This is a brass inner case set for the rear knuckle arms designed for TRAXXAS TRX4 Trail Crawler platforms. The kit replaces the stock inner housing to increase rotating mass at each rear wheel and to stabilise the internal gear train inside the knuckle assembly, which can help with controlled crawling and recovery from low-traction situations.

The package supplies the inner cases plus the stainless steel cap head screws required for assembly, allowing direct replacement of the original plastic housings. The brass components are described as increasing wheel mass to assist with wheel bite and to keep the knuckle internal gears running smoothly under load.

Use this part as a tuning option to alter rear-end behaviour on technical trails where added weight at the wheel hubs helps maintain traction and smoother gear engagement. It is presented as an aftermarket reinforcement for TRX4-series trail rigs rather than a change to steering geometry.

Neutral, install-focused upgrade for TRX4 Trail Crawler owners seeking increased rear wheel mass and more stable knuckle-gear behaviour; check fitment against your chassis before installation.