Im changing my rear differential oil. I believe that this is my fill plug but its not coming loose and im starting to strip it.


Its square on the inside



May have already messed up by taking the cover off.

 

Nah, your fine. Looks like you still have some unrounded square socket left. I would grind down your square driver flat and tap it in. Make sure it is all the way seated, nice and snug. You should be able to haul on it then.

And from the slip marks, are you tightening it?

 

Yes that's the right plug.

Looks like someone has been there before you and ... ,, .... ummm,,, ..... yeah.

Also looks like you're not getting your drive all the way into the socket, possibly due to all the fornication already present. Might want to try a VERY SHORT extension, and a hammer to pound it in.

If worse comes to worst, you can drill it out and use one of those square bolt extractors. NOT one of the "fluted" kind that looks like a real coarse reverse screw, and ABOVE ALL, not a cheeeeeeeep one. IOW don't let the price influence your purchase decision AT ALL. Look at a McMaster-Carr 8289A38 for example.

You can also get a transmission drain plug and put it into your existing cover for filling it with. Just be sure it's about an 1" to 1½" below the center of the axle tubes, and doesn't interfere with the innards. Or, get an aftermarket cover, but if you do that, be VERY CAREFUL not to overfill it. It really sucks when you put in so much fluid that it makes the axle seals leak.

 

I was trying to get it off with a torque wrench. That's when it started slipping. I quit messing with it then. The bolt seems to be really soft. Thanks for the advice. I guess ill be heading to auto zone tomorrow.

 

Don't forget to buy a new fill plug - 1/2" pipe thread.

Use a hammer and a punch if you can't reach the plug with the hammer alone.
Use many SOFT blows on the areas that are deformed outward, attempting to push that metal back where it belongs. DON'T get carried away. The hammer blows will also help break the plug free. Then use the proper square drive bit to remove the plug. You will probably have to tap it into the square hole of the plug. Make sure it is all the way in before loosening. Good luck.

 

It should never strip like that. Its stripping because the square drive you are using is bot going in all the way. Use a good quality short extension, tap it in and make sure its in all the way, then use your ratchet to crank it loose. If you
Need more leverage, slide a piece of pipe over the handle.

No reason why that should come out.

 

Use a 220-volt welder to weld an impact socket (or socket extension) to the plug.

 

Just a shot in the dark (because I've seen some moron do this 2x), any chance someone epoxied it in there to keep it from leaking? If someone did heat it with a torch and it will break down and come out.

 

​​​​​​​It could be. I bought the car a month ago it had been stolen from the previous owners and they neglected it and trashed it. I decided to just leave the bolt in and bought a new cover with a fill and drain plug. Maybe they put some loctight on the bolt? Its stuck in there good.

 

That is a possibility. I bought the car a month ago and the previous owners did alot of things to it that are undesirable. I'm thinking maybe they put loctight on the bolt because it doesn't want to budge at all. I decided to buy a new cover with a fill and drain plug. It looks nice too.

 

from my experience loc tite would never make THAT tight of a lock on the plug, most likely its just from years and years of it never being removed.

as everyone said, make sure the extension is in the square bore all the way. tap it in with a hammer and it will not strip.

 

Yea I did that but its just not wanting to come out. It worked out for the best though because the cover is old and kind of rusted looking.

 

Try heating the plug with a PROPANE torch.
If someone did use Loctite, the heat will release it's hold.

 

I run into rusty ones all the time. I will use my oxy/acet torch and heat the housing up really good. Then they come out.

 

Drain by removing the cover.
Fill with the correct amount through the vent opening after pulling the vent out.
Done.

Sometimes, a stuck bolt or plug is best worked loose by using a tool you can use to rock it back and forth. Breaker bar, or a 3/8 8-pt. socket on a length of square bar. Tighten, loosen, tighten, loosen. When I lived in rustler parts of the country, that helped with corroded fasteners.