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

Brass portal outer housing for TRX4 platforms

This 18-piece set is a brass outer portal drive housing made for TRX4-compatible axles. It is designed to increase wheel-end weight to change crawling behaviour on technical trails and drops in scale rock crawling. The housings fit portal hub assemblies and install with the supplied stainless steel cap head screws.

Material and role: brass construction raises unsprung and wheel-end mass compared with stock alloy or plastic housings, a common tweak to enhance low-speed traction and help a rig recover from digs. Manufacturer-supplied wheel weight figures are provided with the product; validate any stated numbers on your own scales when planning a build.

Fit and installation: the outer housing diameter measures 43mm and the housings need a wheel inner bore larger than 43.5mm for correct clearance. Confirm wheel inner diameter and hub stack spacing before fitting. The kit includes the listed fasteners, but double-check screw engagement and lengths during assembly to protect threads and bearings.

Before installing, ensure wheel inner bore exceeds 43.5mm and that the supplied 2.5mm screws match your hub stack; fit one side first and evaluate handling and steering changes before completing both sides.