Thanks Derek. Yes, I know about the dipstick. I have used a coathanger so far! With the good avice of this forum, I already put 2 liters of oil in the gearbox. I used Redline Heavy Shockproof so I should be on the safe side. I was also wondering about modifying the filler plug in order to leave the dipstick permanently but I have not made my mind about this yet.