Hello all,i decided to change the gear oil on my 2000 2.8tdi it drained no bother the hand book says 2L of oil and on the box there is a 13mm stud its about 30mm long and has a copper washer fitted the hole does take the filling tube [just]but to bring it to the level its over 3.1/2L of oil,when I drained the oil I opened this stud and the drain gushed out approx. 2L or just over.can anyone of you please advise,i have tried to get a manual on this ducato but no luck yet. Thanks.