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

Upper Arm Mount A Compatibility with TRF421X

The upper arm mount A, part number 3451580, is the correct replacement for the 42391 TRF421X assembly. It provides the mounting interface for the upper suspension arm on the TRF421X and is supplied for repair or spare inventory.

Fit and function: the component restores factory suspension geometry without changing kinematic behaviour. When installing, check orientation and secure fasteners to the TRF421X service torque values to prevent binding or excessive play in the linkage system.

Tuning role: swapping in a service mount removes wear-induced deviation so that subsequent setup tasks—camber correction, roll centre checks, and arm length verification—start from the intended baseline.