$1.50 Inc GST
Part Number: 31B447
Often overlooked when doing gearbox rebuilds - this seal is very important as it sits in the very bottom of the case and is the source of irritating oil leaks.
The large round metal plug in the bottom of the gearbox is the pivot pin for all the selector crank levers and this seal sits on it, but is only replaceable when the gearbox is stripped down.