Crown wheel & Pinion 9:31 #
Crown wheel and pinion. 9/31 ratio. This is the standard ratio for Cooper ERSA gearboxes. These are made exclusively for C & G by a leading crown wheel and pinion manufacturer as spiral bevels with helical teeth. The gears are lapped together in pairs after heat treatment and rumbled to improve the surface finish. The pinion set up height and correct backlash are engraved on the parts.