I tried to remove my rear diff filler plug (using the correct tool I might add) and it's so tight it started to round off. I was thinking that worse case scenario would be to drill & tap it.

Anyone have a suggestion how to get it out?

 

I tried removing mine yesterday, cant undo mine either, get the impression its never been undone.

 

I soaked mine with WD40 for ages but still no joy.

Was thinking that because it's started to round off, welding the tool used to undo it to the plug might be the way to go.

I'm not having any issues with the diff, I just thought an oil change would be an easy job so not high on my list of things to do.

 

Heat up the drain plug for a few mins with a hot air paint stripper.


If you are on the drive and still can't get enough leverage you could use your trolly jack under the end of a 1/2" breaker bar (only applies to drain plugs with 1/2" drive recess) instead of using muscle power, worked for me!!!

BTW - The hot air paint stripper trick works for brake pipe unions too (the heat softens the gummed up brake fluid between the threads).


Disclaimer - hot air paint strippers get hot so try not to set your car on fire

 

Breaker bar didn't work. Think I'll get it to a garage and see if their air wrench will loosen it.