TRX4 Portal Outer Drive Housing Set 6061-T6 Aluminium Trail Upgrade TRX4021A by GPM  [TRX4021A]

6061-T6 Portal Outer Shells for TRX4 Trail Crawler

The TRX4021A outer portal drive housing set is supplied as 18 pieces to replace the plastic outer shells on TRX4 Trail Crawler knuckle assemblies and can be used on either the front or rear axle. Manufactured from 6061-T6 aluminium, these housings give a stiffer mounting plane to help keep inner portal gears accurately aligned while negotiating rough terrain.

Stainless steel cap head screws are included for assembly and the housings are sized to align with the original plastic neighbours, allowing a mostly plug-and-play swap that avoids altering nearby components. The 3D-machined body and precision-cut edges help preserve correct gear meshing and running clearance in portal stacks.

These housings are intended to stabilise inner gears within the portal housing, cutting down flex that can upset engagement and steering response on technical sections. They support installation on front or rear portals and note a midpoint measurement of 93mm between damper and tie rod for basic siting on standard TRX4 knuckle arrangements.