Stripped differential fill plug

[purple78monte]

So I noticed the seal for my diff cover started leaking so I drained the fluid and while that was draining I went to take the fill plug out and stripped it pretty bad I tried welding a bolt into it with no luck same when I tried to weld a nut onto it and I’ve tried drilling into it and using an easy out but I can’t get it to break loose the bit will bite in but I get anything bite on the end of the bit I’ve tried drills a socket and an impact a socket and ratchet I even tried welding the socket onto the end of the easy out and still nothing and I’m kind of out of ideas of what to do does anyone have any suggestions of what to do

 

[ELCAM]

Drill it out as big as you can without damaging the threads in the axle housing. If you get it thin enough it wont have any strength left.

 

[Rt Jam]

Is the fill plug on the the cover or casting?

 

[purple78monte]

Is the fill plug on the the cover or casting?

It’s on the casting on the passenger side right near the yoke/pinion

 

[69hurstolds]

Did someone re-install it with red loctite or something? And/or use star torque to tighten it? Either that or a lot of corrosion is at play here. They're pipe threads and it seems unnatural to not be able to break that loose. It's not like it's 4 feet thick.

 

[buick7332]

So I noticed the seal for my diff cover started leaking so I drained the fluid and while that was draining I went to take the fill plug out and stripped it pretty bad I tried welding a bolt into it with no luck same when I tried to weld a nut onto it and I’ve tried drilling into it and using an easy out but I can’t get it to break loose the bit will bite in but I get anything bite on the end of the bit I’ve tried drills a socket and an impact a socket and ratchet I even tried welding the socket onto the end of the easy out and still nothing and I’m kind of out of ideas of what to do does anyone have any suggestions of what to do

I would try a dremel with a metal cutting bit and carefully remove the plug right to the threads and then run a npt tap through the hole. Take your time and be careful not to cut into the threads. This has always worked for me.

 

[Built6spdMCSS]

Yea considering you put gear oil in that hole one would think the threads would get lubricated well.

Aren't they 3/8" square, you stab an extension in it and use a ratchet.

 

[SS_Malibu]

If you drill it out just remember where those metal shavings will be going.
You'll need to pull it apart and clean the inside of the housing out to be sure you have no metal chips inside.

 

[Built6spdMCSS]

Drill it holding a shopvac next to it, done that on a few things.

 

[Bonnewagon]

If it is that bad, then move your fill hole to the cover. My Jeeps use a crappy plastic fill plug that leaks so I weld an O2 bung to the hole and use a bung plug to seal it. Just locate the hole at the same height as the stock fill hole and fill as usual. It is actually easier to use then the stock hole due to lack of obstructions.