GPM TRX-4 Brass Inner Front Knuckle Arms TRX4021BX - RC Spare Part  [TRX4021BX]

Brass inner front knuckles for TRX-4 crawlers

This upgrade set replaces the inner front knuckle components on TRX-4 scale crawlers with brass arms engineered for repeatable fit and extra mass. Each brass arm is precision machined to preserve smooth rotation at the knuckle pivot while adding stabilising weight for low-speed trail driving. The parts are intended for RC-scale use only and not for any real vehicle applications.

Installation notes: the brass inner knuckle locates in the knuckle inner case and is assembled using the supplied stainless steel fasteners. Check alignment and bearing clearance during fitment and apply a moderate threadlocker to the button head screws where needed to prevent loosening from vibration. No special tools are required beyond common hex drivers for the listed screw sizes.

Included hardware and parts: inner part front knuckle 2pcs, stainless steel round head screw 3x16 2pcs, stainless steel round head screw 2.5x3 6pcs, stainless steel button head screw 2.5x8 4pcs. Each brass arm adds roughly 50g of external weight potential so you can tune front bias for improved traction and stability on steep or technical sections.

For TRX-4 owners after a durable inner knuckle replacement that adds front-end ballast, this brass set is a straightforward swap that changes traction and steering feel without altering mounting geometry.