Front Diff - Oil Capacity?

Just changin me front diff oil.
Took her for a run to get it warm, then drained old oil, leaving it for a good 20 min, with both filler and drain plugs out.
In the process of re-filling and I've got 1.2 litres in and it's up to the filler hole.
According to Paynes, it should take 1.7 litres to re-fill?

Am I missin sommat, or is Paynes wrong again?

(Yes the Landy is on the level, and I have left it to settle for a while before re-checking).

I managed to get about 1.5 into mine. I then jacked it up a bit at the front and filled it up.

I got 1.7 into mine, but i didn't drain any cos it had done it by itself for me...

Had been run dry by the previous owners for a long time, and i filled it up and put a cap on the end.

You may find that there is residue etc in the diff housing taking up space, but i wouldnt have expected that much space.

Thanks for the replies.
Looking at it a bit closer, I think I can see the problem.
I had a new diff pan fitted last year and it looks like it's gone on turned slightly clockwise, so that the filler plug is a bit lower than it should be. Anyway, I jacked the front up and topped up to 1.5 litres - didn't want to over fill.