It may not have been completely empty when you attempted to fill it.
The front axle (on most) has two chambers in addition to the main housing. The left and right wheel “bevel gear case” …each of which holds a significant amount of oil.
If the front axle is serviced with oil…but both bevel gear cases were not completely emptied….then the specified amount cannot be added.
Correct. Not my first rodeo.
Drain plugs were removed as well as fill plug, so as not to impede drain. Allowed a couple hours to do so.
Geometry of the axle is pretty complicated. Makes drainage less complete. Not like motor oil pan.
Many rated capacities are reflective of first fills when new and dry. Changes/refills sometimes don’t reach rated capacities fully, as the drain is not 100%.
I’m sure you’ll have a rebuttal. You’re a LOT smarter than I am. Feel free.
I’m out.