Yokomo R12-10U Upper A-arm  [R12-10U]

Upper A-arm for R12/GT series

This replacement upper A-arm is supplied as a standard service part for the Yokomo R12/GT family. It is intended as a direct-fit swap for worn or damaged upper arms and to support routine setup changes during chassis tuning. The description below focuses on compatibility, fitment notes, and its role in suspension geometry adjustments.

Compatibility is limited to the listed R12/GT variants. Confirm fitment against your chassis model before purchase to ensure the arm matches existing mounting points and ball stud locations.

Supported chassis: GT5-R35, GT5-SC430, GT3-REA, GT3-IS350, GT3-B4, GT3-CAX, GT3-BRZ, GT3-AHP, GT-B, GT5-R2, GT5-RS2.

Installation notes: This A-arm installs using the chassis' original fasteners and ball studs. During replacement, inspect the hinge pin and bushings for wear and verify suspension alignment (camber and toe) after installation. Tighten hardware to the vehicle manufacturer's recommended torque range and verify free movement through suspension travel.

Tuning role: Upper arm condition and geometry affect camber gain, roll center height, and steering return characteristics. Use this part when restoring baseline suspension geometry prior to finer adjustments with shocks, sway bars, or toe links.