I changed the gearbox oil of my Ibiza 1.9 tdi 2008, drained it when engine was warm and when refilling it, the car was level, I could only get 1.6 Litres of oil in, before it came out of filler hole, the manual says it takes 1.9 Litres, anyone else experienced this? I used full synthetic 75W gear oil as stated in manual.