TRF421X Upper Arm Mount B 3451581 compatible with Tamiya  [3451581]

Upper Arm Mount B - TRF421X Fit Details

This is the replacement Upper Arm Mount B identified by part number 3451581 and linked to code 42391 for the TRF421X chassis. The item is provided as an RC-scale spare meant to restore or change the upper arm mounting position without modifying the surrounding suspension or arm assemblies.

In use, the mount locates the upper arm relative to the shock tower and suspension mounting plate, so it affects ride height, camber roll center, and lateral stability when used during setup revisions. Use the part to swap out a damaged mount or to preserve correct geometry following maintenance.

Fitting is simple for hobbyists with common tools: remove the existing mount using the original hex screws, align the replacement to match factory orientation, and secure with the same fasteners. Check arm movement and suspension for binding, then re-check wheel alignment after the initial test drive.

Provided as a direct-fit spare, this component is intended for TRF421X users who need a replacement for part 42391 or who are making chassis geometry adjustments during tuning.