TRX-4 Brass Inner Knuckles for Trail Use TRX4021BX by GPM  [TRX4021BX]

Brass inner knuckles tuned for TRX-4 crawling

This brass upgrade replaces the inner front knuckle components on TRX-4 scale crawlers with heavier, precision-machined pieces for stable fit and added ballast. The machined surfaces keep the knuckle pivot operating smoothly while the extra weight helps the truck hold lines at low speed. These items are for RC use only and are not suitable for road vehicles.

Assembly notes: the brass inner knuckle locates into the knuckle inner case and uses the supplied stainless steel fasteners for a secure build. Verify bearing fit and alignment during installation and apply a moderate threadlocker to the button head screws where appropriate to reduce screw backing. Standard hex drivers cover the required fasteners.

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 offers about 50g of external weight potential so you can fine tune front bias for better traction on rock or trail sections.

For TRX-4 owners after a simple, durable inner knuckle replacement that increases front mass, this brass set provides an easy swap that changes traction and steering feedback without altering mounting geometry.