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

6061-T6 Outer Portal Housings Compatible with TRX4

The TRX4021A outer portal drive housings are supplied as an 18 piece aftermarket set made for TRX4 Trail Crawler knuckle assemblies, suitable for front or rear use. Fabricated from 6061-T6 aluminium, these shells replace the stock plastic outers to create a firmer mounting location that helps retain inner gear alignment during slow technical crawling.

The package includes stainless steel cap head screws and is sized to allow direct replacement with the original plastic neighbours, enabling an uncomplicated swap without trimming or relocating adjacent items. The housings feature a 3D-machined profile and sharply cut edges to retain correct mesh and clearance for portal gears.

In service the part reduces housing flex to stabilise inner gears, improving consistent engagement and steering precision on demanding sections. It fits either front or rear portals and lists a midpoint damper-to-tie-rod measurement of 93mm as a basic reference for positioning on standard TRX4 knuckle arrangements.