TRX4 Outer Portal Drive Housing Set 6061-T6 Aluminum Gear Stabiliser TRX4021A by GPM  [TRX4021A]

6061-T6 Aluminum Outer Portal Housing for TRX4

This TRX4021A aftermarket outer portal drive housing comes as an 18pcs set for fitment to TRX4 Trail Crawler knuckle assemblies and is suitable for front or rear installation. Machined from 6061-T6 aluminum, the housings replace the original plastic outer shells to provide a stiffer mounting surface that helps maintain inner gear alignment while crawling.

The kit includes stainless steel cap head screws for assembly and is dimensioned for a straightforward swap with the stock plastic neighbours, letting most installations be plug-and-play without modifying adjacent components. The housings use a 3D-machined streamlined profile and precision-cut edges to preserve gear mesh and clearance in portal stacks.

Functionally the parts stabilise inner gears inside the portal housing to reduce flex that can disrupt gear engagement and steering feel on technical trails. They are suitable for use on either front or rear portals and reference a midpoint distance between damper and tie rod of 93mm for basic siting when fitting to standard TRX4 knuckle layouts.