Does anybody know the reason why the filler holes on the transfer box and Haldex are not also the oil level holes which seems the logical thing to do when designing these units.
Also has anybody filled them to the filler hole level ran their vehicles for some time and suffered any problems.
I am not planning to do it just curious.

When putting oil in one hole you keep going until it appears in the other hole, then you stop

Is that the hole management are looking into?  FL2 MY10 TD4 GS traded in at 2 years
FL2 MY13 TD4 GS Current

Ask a sensible question and get a sensible reply, some hope!

Yes its intriguing as to why you fill something with very expensive oil and then take out a spoon full and throw it away.

Could be several reasons to include machining tolerances or higher level needed to transfer oil to all the working areas prior to use but running level lower to stop hydrolicking in use.

https://www.freel2.com/gallery/albums/userpics/11383/haldex.jpg FL2 MY10 TD4 GS traded in at 2 years
FL2 MY13 TD4 GS Current