[ajchien]

I agree with traylaw. You need to find ways to increase your ability to create leverage. You can raise the car higher on the jackstands to give yourself more room. You can add an extension into the hole so it seats better, and bonus the extension might be indexed differently so your breaker bar can have more swing arc. Alternatively, you can get a longer 3/8” handled ratchet, or adding a cheater pipe onto it. And if all else fails, consider what the fish did with a floor jack:

 

[ajchien]

used a major compnanies one

NEIKO 00339A 3/8" Drive Premium Breaker Bar | 12” Length | 180 Flex Cr-Mo Head | CR-V Steel Construction - - Amazon.com

NEIKO 00339A 3/8" Drive Premium Breaker Bar | 12” Length | 180 Flex Cr-Mo Head | CR-V Steel Construction - - Amazon.com

amzn.to

Husky rachet was what you seen me snag it off with fish

I might even suggest going bigger:

Amazon.com

or even a 24” long 1/2” drive tool. Ive gotten to the point where I’d prefer to buy the tool that makes things easier rather than to have wear and tear on the body trying muscle something off.

 

[ajchien]

Thanks for the suggestions guys! I guess the dealer may be a good idea here. Although, the other ideas given here are pretty good, and may be worth a shot. The impact I was using was a 1/2 inch electric Ridgid impact, I'll throw a link for it down below. Its crazy, I have been able to remove any other fill bolt I've tried, but this one is something else! And then with the silicone being so close, heat doesn't seem to be an option unfortunately. If I do take it to the dealer this time around, then should I crack the fill bolt off when I get the car back home and do something to make it easier for the next time so I don't have to take it to the dealer again? From my experience, dealers usually torque things down with a few ugga duggas making it difficult next time I try to DIY.

RIDGID 18V OCTANE Brushless Cordless 1/2 in. Impact Wrench (Tool Only) with Belt Clip R86011B - The Home Depot

RIDGID introduces the 18V OCTANE Brushless Cordless 1/2 in. Impact Wrench (Tool-Only) with Belt Clip. OCTANE Tools feature high performance brushless motors and advanced electronics, providing best-in-class

www.homedepot.com

Im curious as to what kind of adapters/universals/extensions you used with the impact wrench.

FWIW, I would have never even thought about using an impact wrench for the two differential plugs. Ive always used ratchets or breaker bars, usually around 15” in length.