TRF421X Upper Arm Mount B 3451581 for Tamiya  [3451581]

TRF421X Upper Arm Mount B Overview

This replacement Upper Arm Mount B carries part number 3451581 and is linked to code 42391 for the TRF421X chassis. It is supplied as a like-for-like spare to restore or adjust the upper arm mounting point without altering adjacent suspension or arm components.

Functionally, the mount locates the upper arm relative to the shock tower and suspension mounting plate, so it directly influences ride height, camber roll center, and tracking when used during setup changes. Fit this part to replace a damaged mount or to retain correct geometry after routine maintenance.

Installation is straightforward for hobbyists with basic tools: remove the affected mount using the original hex screws, position the new mount in the factory orientation, and secure with the same fasteners. Verify arm travel and check for suspension binding before running, and re-check wheel alignment after the first test outing.

This component serves as a factory-fit spare intended for TRF421X owners who require a direct replacement for part 42391 or a serviceable option while tuning chassis geometry.