Not true. There are Dana 44's used on Jeeps where seals have been blown due to overfilling due to filling to the plug level. This F-1 uses a Dana 44, hence the question.
Also, another thought. The axle should have a breather, as long as the breather is open and working there should not be any blown seals. If it doesn't have a breather it needs to have one added. That is something else I added to my quick-change.
Hi Martin, I have seen those type breathers, where the brake union bolts on. I THINK the bolt is a special item, with a hole up the middle and a loosely fitting metal cap that goes over the end. If one were not "in the know" and assembling and axle up from parts, if a normal bolt were used by mistake, the axle would not be able to breathe.
I seem to remember one with a metal cap like that on a 9" axle.
Mart.