there are 2 plugs 1 the fill plug is on the side of the box which you will get at if you lock your wheels over to the left it is at the back of the front passanger side wheel arch......
and the drain plug is under the the box it is under the diff.... basicly where the drive shafts enter the box its under this it will look like the fill plug 17mm allen key how much oil you need i dont know as ive only got the nk 2 book.....
normaly you fill the box until the oil starts to run back out of the fill hole! make sure it does run out and its not running back out because your putting it in too fast...
and early gearboxes had a different fill technique.........
something like you have to fill it up normal and then add 250ml or 500ml through the speedo cable hole!
because of the fill put is too low..... on later models they revised this.......
someone should know more about this...
use a synthetic oil..... this will help stop cold crunch gear changes and will help the box last longer
