YOKOMO R12/GT series Shock Spring Cup for R12-37C by Yokomo  [R12-37C]

Product overview and fit

This spring cup is designed for use with Yokomo R12/GT series touring car shocks and secures the coil spring onto the shock shaft, giving a clear reference for preload and travel adjustments. The component aims to provide accurate spring placement rather than altering the spring rate itself, and it integrates with standard shock maintenance procedures.

Fitting steps: remove the shock cap and any collars required, slide the cup into position on the shaft seating area, then reassemble making sure the spring sits squarely. Use appropriate small hand tools and inspect for any play after refitting. A press is not typically needed for standard compatible shock bodies.

Tuning advice: changing the cup position affects effective preload and the initial travel stop, which can change ride height and transient response. Make incremental adjustments and test to find preferred handling. Regular checks for burrs or distortion will keep spring seating consistent.