Front diff drain plug stuck

I'm at a loss at this point. My front diff drain plug is as stuck as stuck can get. The hex hole has been stripped to hell, I've gone through a can of PB Blaster, I've torched it and chiseled at it and it still won't budge. I'm not inclined to drill it out because I don't want to get metal shavings into the diff, and I'd rather not tap new threads either since I already spent good money on the Australian 19mm hex head replacement. Short of welding on a nut and using that to get it off (I don't weld and don't know anyone who does), I'm out of ideas. Any suggestions?

 

The welded nut is probably the best option at this point. Is it drivable? Can't cost that much to get a muffler shop to weld on a sacrificial socket

 

Exactly. Just take it to a shop and they’ll make short work of it.

 

A small independent auto shop would be the best option.

 

I'd try to drive a torx bit into it. T-55 maybe. If you can get it to jam in tight, use an impact driver to loosen. Don't pound so hard that you crack the case. Since it's the drain plug, one option is to suck the oil out through the fill port. Welding a nut on may be the best option if the Torx bit doesn't work.

Good luck

 

Buy Lexus plugs

Weld nut

Wrench it off

 

Yep, then call it done,,,, just make sure whoever welds the nut can actually weld. Plus the heat will work to your advantage once it cools off a little.

 

OP is in California; if he's in the Central Valley we can knock that shit out quick

 

I ran into this on my 3rd gen’s front diff a couple of months back. I was going to have my neighbor weld a nut on for me but I decided to give it a go on my own first. I used a die grinder to grind a groove in the plug and then used a chisel and hammer to slowly “loosen” it until it started to back itself out. I douched it down with quite a bit of pb blaster for a couple of days before I tackled it. Then replaced it with the lexus plug like some others mentioned. Good luck.

 

But can you remove the fill plug? Always do it first.

'Cause if you get it drained, but can't refill, you have a bigger problem.

 

The fill plug comes out fine fortunately.

I'm going to call around tomorrow and see if any shops are willing to weld a nut on for me. Thanks for all the replies, everyone

 

I’m not a welder so I don’t know about this, but when I asked my neighbor about doing mine, he said we should have the fill plug out to allow the welding heat to better escape.

 

The oil will absorb the heat, not necessary at all.

You can even fully weld a skid on these things without issue.

 

@Kwikvette mentioned Lexus plugs, which is totally the right way to go. Here are the two plugs you need: https://adventuretaco.com/a-front-diff-drain-fill-plug-that-doesnt-suck/

 

I’m dreading getting mine out.

Would something like this work?

 

This is what I do -

If in doubt, use penetrating oils and spray 24 hours before tackling the project

Get the correct key sockets for the drain and fill - of course, remove the fill first before the drain

Use a metal pick and clean/scrape out any and all dirt and grime that builds up to ensure your socket will seat as far into the plug as possible

Place keyed socket in the plug, and whack the backside of it several times to break up any rust

At this point you should be able to remove it without issue

 

When you say “keyed socket” you’re just referring to the 10mm hex/allen needed for the front diff drain plug, correct?

 

Yes sir, just easier saying it as I did because mine are in my tool box so I don't know what size they are

I will say, I used a 1/2" drive for the drain and only a 3/8" drive for the fill

Don't remember why, but definitely use at least a 1/2" drive for the drain so you get some good leverage on it

 

angle cutter, then chisel it away counter clockwise

 

@Madjik_Man This is what I do as well.

To add a bit of emphasis - getting the 10mm hex/allen seated well/deep is very important. And, before doing that, use a hammer (like, a real metal nailing hammer) and firmly hit the drain plug a couple of times, That shock can help loosen it up a bit, and has always worked well for me.

The one other thing that can be useful - hex wrenches are notoriously short - like 6-8 inches. Get a length of 3/4"x3/4" tubing (or something you can use to increase your leverage). Something in the 18"-24" range will make a world of difference, and that leverage is fine as long as you have the hex wrench fully seated.