So, after draining the rear diff and the transfer case and refilling it came time to do the front diff.

Flashback: I had the diffs drained and refilled a previous time at a place that managed to eff it up by not torquing the filler plug all the way done (not to mention not using a new crush washer that I had given them). At the time, I put a new crush washer on and cursed them for having to clean gear oil off the skids. Didn't even think at the time of checking the drain plug, because there wasn't anything leaking from it.

Fast forward to today: The drain plug is either cross-threaded and stripped, or at the very least just stripped. What a PITA! Anyway, after successfully stripping it more, I get the dremel out. Cut a notch, get a chisel and hammer and start whacking away. Not even a bit of a budge.





Well, this is why they make screw extraction kits. So, I pull the screw extraction kit out along with the drill. Get into it and start the extractor. Seems to be biting pretty good until:





No idea what to do now. The diff isn't leaking or anything, I just wanted to replace the stripped drain plug with a new one.

Weld a 17, 19 or 21 nut onto the drain plug.

1. Weld a nut onto it and remove. Probably don't have a welder. Consider buying one in the future. Handy to have.
2. Buy a screw extractor, multi spline type, just a little bigger than the size of the hole, hit it in there, heat with oxy/ace and then attempt to remove.
3. Probably won't work but take a correctly sized extension, hit it into the hole to where it is snug, then put an impact on the other end.
4. Cut a groove into the plug, take an air hammer with a flat tip chisel bit and hit it enough to where it hopefully spins free.

#1 is the quickest and should be cheapest....

Good luck

i ran into the same situation on my 4runner, previous owner stripped the hex, tried the chisel method but that didn't work the first time, then i heated the case slightly with a torch and used the chisel again and that worked for me!

Haven't tried heat yet. That's the next option I think.

Those really seize in there. My last 4runner stripped out with a 2 foot breaker bar on a snap-on hex socket. Fitment was great it just couldn't handle it. My current truck I used my new cordless impact and it shocked the cover right out. I know if I had done (or had for that matter) this big ass impact it would have removed the other one too.

Since you stripped yours as well, I used a siphon pump with a necked down tube and siphoned the fluid OUT of the differential and then added fresh gear oil once I felt it was mostly emptied.

I used the $8 siphon pump from harbor freight and it has always worked well for me until it surpasses maybe 20 quarts through it. It has the smaller hose that fit down inside the diff casing though I believe.

Like stated weld a bolt. Bet shop charge half hour labor.

Not to threadjack but does anyone have a thread spec or alternative part # (eg. From different manufacturer with a non hex head) to replace the shitty OEM designed plug with?

the hex plug used in the rear diff should be the same thread/size

i couldn't remove the plug, but i got the fill plug removed, so i got a pump to remove old oil and fill in new ones.

Just dealt with this yesterday. What I did was get a drill and create a square shape in the drain plug, just the right size for a 3/8" ratchet extension. Then I hammered an extension into it and was able to get if off by connecting a ratchet to the extension and twisting. That was my non-welding way of getting it out, hope that helps.

You can probably use the same method you're using by adding one more step. Grab your hammer and hit the face of the drain plug very hard a few times, it helps to crush the gasket down making it easier to loosen the plug. Then go back to using the chisel. I use this method at work to remove them when they're stuck.

I just weld something to it to get it out and just replace it. And when I put the new one I put some Anti-seize on it


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If I was going to weld a nut onto the plug I think I would keep using that plug. It's already got a nut on it now!

Next time, for this application I would use this type of extractor.

Hex Head Multi-Spline Screw Extractors - 522/532 Series - Tools - IRWIN TOOLS

These plugs always seem to need some impact to get them off though. I would think you're on the right track with the chisel technique. Some heat should do it.

I have never had a nut or bolt that some Kroil couldn't bust. It's leagues above even PB Blaster. A little pricey, but SO worth it. I usually spray it on heavy, leave it for 30 minutes, then spray again right before I wrench on it. Works every time - seriously. And my truck is literally eaten alive with rust...

Hey, another thread I can post this video in.