A key element of the gearbox ratio ! This SADEV 4th gear pinion, 23 teeth (P/N: F1903003 ), mates with the 26-tooth 4th gear wheel to provide the specific 4th gear ratio for your Renault Clio 2 Gr N's ST66 dog-ring gearbox . Wear on the teeth or damage to the dog rings of this pinion results in difficult...