31 teeth Idler Gear, with one shaft longer than other as per last Rover design modification.If the Mini drive train has a weak link, it's the connection between the engine and the transmission! The idler gear often takes the abuse caused by wear and/or poor assembly techniques. To avoid problems or expense of correct shims, bearings see
C-22G943 We see more original idler gears go bad than we do any component in an engine! For the 4-synchro PRE A+ transmission.