TRF421X Upper Arm Mount A Replacement 3451580 for 42391 by Tamiya  [3451580]

Replacement Upper Arm Mount A — TRF421X Fit

This upper arm mount A is the designated replacement part 3451580 that fits the 42391 TRF421X assembly. It provides the fixed attachment point for the upper suspension arm on the TRF421X and is supplied as a straightforward spare for routine maintenance or crash repair.

Fit and function: the component is made to restore original suspension geometry so the kinematics remain unchanged. During installation, check the mount orientation and fastener torque against the TRF421X service guidance to prevent link binding or excess play.

Tuning role: replacing a worn or damaged mount returns the arm to its baseline position, enabling further setup work—such as camber correction, roll center checks, and arm length verification—to proceed from a known starting point.