Added pressure? The ZF document suggests there is an overflow outlet from which it would escape, that suggests it is not sealed
You're probably correct, but I'm concerned that I wasn't able to get as much in to my transmission on the initial fill as people seem to report. I've seen many people saying the initial fill was 3.5lt but I got nothing like that in there - somewhere between 2-2.5lt (allowing for some still being in the pump). I can't see any logical reason for this considerable difference can you suggest one? I mean there are no variables relating to that. We're simply talking about initial filling of the oil pan up to the filler level, no engine running, no running through gears etc.
If you look at the transmission, with the car horizontal, it slopes down from front to back quite a bit - so much so that if you visualise where the oil filter intake sits and the level that the filled oil must be sitting at relative to that intake, it's quite possible that under acceleration or while going up-hill that intake isn't going to be sucking up any oil. That seems a bit worrying?
Did your E34 and Audi transmission sit parallel with the ground with the vehicle horizontally level or were they offset at an angle like the X5 is? In the ZF document it does show a diagram of the Audi version of this transmission but it shows it level which may or may not represent it's actual orientation.
As for checking the amount of oil fluid coming out, that would not have worked for me as I had a leaky sealing sleeve and gasket so suspect the level was low in the first place. What I do know is that with the transmission level (not the vehicle) I put in approx 5.5lt excluding overflow etc.
The oil change has solved my annoying squeal when changing up from 2nd to 3rd under moderate acceleration.
I'm going to do this again in the next week to cycle out more of the old fluid so want to make sure I do it right.
On the fluid temp, I kept INPA running when I went out for a test drive after completing the change. It seemed to settle around 85'C. I don't know if that's good or bad.