Front diff fill bolt

[George Owens]

I just did mines not that long ago, I used liquid wrench the three days up until I did it and had to use a little bit of muscle

You might have to bite the bullet and have it professionally removed

 

[swat2380]

Mine is stuck from whoever previously serviced it. No biggie I filled it from the drain plug using a marine lower unit pump you can buy anywhere for around $10. Give it an extra pump or two for the split second you switch back to the drain plug and done.