Bad photo of me feeling very smug having invented the "Acme" differential oil filling system consisting of a pile of boxes, clamp, funnel, lots of jubilee clips and smaller and smaller hose, ending up poked into filling port of rear diff. The oil is very thick (Millers diff oil), the idea was to fill the funnel, leave it for a bit and have a beer, come back and add some more, repeat until full volume in the diff.

30 min later it was thumbs down: I had big puddle of slime on garage floor as an air lock had stopped the oil going into diff and it just overflowed. I could not get the mid level drain port off (to let air out as it filled) so in the end I added about 7 pints of treacly oil to diff by lying under car with a 50ml syringe for about 3 messy hours until 2am. Another lovely job done.