Can your transmission fluid leak into your front differential?

For auto, most certainly and it’s a common issue. 

For manual, the gearbox shares oil with the front diff. 

Cheers 

Bennie

It’s an automatic is it hard to fix

There are seals between the transmission section and the differential section.   If they fail,  atf will end up in the diff.   The diff case will gain oil.  It is a pretty bug job to get to them, dissasemble most of the transmission to do it.

 

The other sneaky leak for atf is the vacuum modulator.  

Don't worry about it. Just run ATF in the diff. It will be fine. 

GD