gearbox oil astra mark 5?

level plug n/s inner drive joint,13mm plug, usually take the breather out from the top of g/box and fill from there

wickham
August 2010

you do not say if manual or auto box, drain plug should be on the bottom of box,filler could be on the side of box, or look on top, but the best way is to get a haynes manual, this gives you all details you need, because, if you are not sure what you are doing, then you could cause very expensive damage to your g/box if you go wrong.

hope it helps
August 2010