Last winter I drained mine. Only a small amount of thick black liquid was in the pan while draining all night. I then ran kerosene through a few times to hopefully clean out any remaining black liquid. I then filled with Redline to the fill hole and plugged it. Then I added quit a bit more through the vent hole using a special squirt bottle. In my opinion that little bit of oil to the fill hole is not near enough! Put some oil in it! It now runs very quiet and I haven’t noticed even one drop leaking through the vent. Think about it....all the differentials like a Ford 9 is filled at least half way full.
High Noon
Careful !
I suspect but cannot prove that overfilling the box in this way caused the front oil seal to start leaking.
The vent was clear and no oil was lost via the vent at that time.
