Hey all, my rear differential has had a small leak for a little while so went to put in a new gasket. Before I took the cover off I tried to take out the plug, well nothing I have tried had been able to budge it. I have used PB blaster, heated it up a little, impact gun, it will not budge.

Is there another way to fill the diff. up without being able to remove the fill plug?

 

If you have a 10-bolt rear end, I would say the answer is "Not with stock parts." However, there are some aftermarket goodies, like this:
Camaro 10 Bolt Rear End Cover | F-Body 10 Bolt Rear End Cover

I just Googled "10 Bolt Covers" and a bunch came up. Notice that they have a plug in them!

That said, most people pay as little attention to their rear ends as they can get away with, unless changing gears or putting in a posi. Most people have no idea just how much those things flex around inside under load and there are covers that are strengthened to reduces the flex and could save your rear end....in more ways than one! ; )

Finally, and just for the record, as long as we are talking about rear ends at all, let's talk about Cooling...those things take a lot of abuse and the only cooling they get is that sheetmetal cover. Those cast covers with fins really will do you some good under load, and look cool, too. Actually, this is true for Valve Covers and Oil Pans, too, if you need an excuse to buy them. : )