TRX4 Compatible Outer Portal Housing Brass Heavy Edition 18pcs TRX4021XB by GPM  [TRX4021XB]

Heavy brass portal housings for TRX4 axle upgrades

This 18-piece brass outer portal drive housing set is intended for TRX4-style portal hub assemblies and is used to raise wheel-end mass for improved traction on technical terrain. The housings are designed as a drop-in for compatible portal setups and secure with the supplied stainless steel cap head screws.

Material and role: brass increases unsprung and wheel-end weight relative to stock alloy or plastic housings, a known method to improve low-speed grip and help a crawler recover from digs. Any weight figures included with the product are manufacturer-supplied notes; confirm them on your own scales if required for precise setup.

Fit and installation: the housing outer diameter is 43mm and requires a wheel inner opening greater than 43.5mm to avoid interference. Check wheel inner diameter, hub stack clearance and screw engagement during initial fitment to prevent binding or thread damage.

Confirm the wheel inner bore is above 43.5mm and trial-fit with the supplied screws; assess handling on one side before fitting the housing to both ends to dial in suspension settings as needed.