Surprisingly, most manufacturers no longer make provision in the expected manner viz a filler orifice, nor for that matter do they provide a means of draining the gearbox! This begs the questions "why do you need to top up the oil?" and "where has the oil gone?" In any event, the usual method of adding oil is to remove the speedometer sensor and use a syringe to add oil. Don't overfill it!
Graham Read, July 2009
