Transfer Case Fill Plug - Stripped!

[eldplanko]

I know this one has been discussed before, but I'm at my wits end on this.

Relevant info:

1998 Suburban K2500, >8600 GWVR, 4L80 trans, NP246 diff

I have the old style (1/4" drive aluminum fill plug), which I've managed to strip round. I spend the day today trying to get it out, only to make the hole bigger and bigger.

Here's what I've done:

Pulled the torsion bars our, and removed the torsion bar crossmember that sits just rearward (about an inch or two) of the transfer case to get a bit more access to the plug. Used heat (MAP/propane), pounded various size torx bits into it (T45, T47, T50 and T55; as you can see the hole is getting bigger and bigger). As far as extractors, I tried a 1/4" pipe nipple extractor (its the least tapered one I could find). My other extractors had too much of a taper to ever get a bite. Finally, cut my biggest extractor in half with a grinding wheel to get as much in contact with the hole... still nothing. The old plug metal is so soft, nothing can get a bite into it. I tried spraying with penetrating oil, but the entire thing is vertical, most just runs off. I've thought of the old "make a little dam" out of putty trick to hold some up there; I'm not sure it's worth it considering I can't get a bit. I'd be suprised if I ever got more the 30 foot pound on it (calibrated elbow).

Right now there's about a 3/8" hole about 1/4" deep in the plug.

I'd prefer not to have to pull the entire transfer case off. I could probably drill it out as it sits, I'm mostly worried about the metal shavings that will end up inside.

Any thoughts, suggestions, encouragement, or "you're screwed" is encouraged. I'm not really screwed though... the t-case runs just fine; I'd just prefer not to have to slap the "run till fail" sticker on it.

 

[magimerlin]

Got a pic of what's left? It enough meat is still there you might be able to groove it with a dremel or something like you do with a stripped screw head.. basically make a flat head screw outta it, sorta..

 

[bullas1022]

Can you get a drill in there? i normally try to drill all the way through the plug to try and get it to shrink a little, then pound an easy out into it and try and remove it

 

[90W7]

What a pain. I would just drill it thru slowly and then use the corresponding ez out/extractor. Hopefully that can get a good bite on it And then flush it the best you can to be safe with more ATF.

I assume there isn't enough threads showing to latch on with vice grips.

 

[wildncrazyguy]

Will be watching this one. I too have a 98 Suburban, recently acquired, same situation. Fill plug is stripped. Bought me a heat gun yesterday at Lowes as there is a technical bulletin regarding this issue I found and GM recommends heat gun to heat around the case, not the plug to try removal. This is of course before you wallow it out I'm assuming. The previous owner or shop he carried it to did a pretty good job. I haven't yet touched it, just took a couple of pics to see what I was in for, but am probably the same boat as you, so I'm pulling for you and please post how you got -er out please.

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[SCOTTYINWV]

I would cut a notch in one side of the plug to wedge a flat head into, use some heat and Tap the end of the screwdriver in the right direction out of the threads. Like how you use a punch to tap out a fuel pump lock ring.

 

[eldplanko]

I would cut a notch in one side of the plug to wedge a flat head into, use some heat and Tap the end of the screwdriver in the right direction out of the threads. Like how you use a punch to tap out a fuel pump lock ring.

I had previously tried the brute force version of that (cold chisel on the edge counter clockwise after heating with the torch; no go)... it's nice to see we all have the same bag of tricks! I'm thinking of drilling through and using the square style extractor next.

 

[eldplanko]

Will be watching this one. I too have a 98 Suburban, recently acquired, same situation. Fill plug is stripped. Bought me a heat gun yesterday at Lowes as there is a technical bulletin regarding this issue I found and GM recommends heat gun to heat around the case, not the plug to try removal. This is of course before you wallow it out I'm assuming. The previous owner or shop he carried it to did a pretty good job. I haven't yet touched it, just took a couple of pics to see what I was in for, but am probably the same boat as you, so I'm pulling for you and please post how you got -er out please.

You must be registered for see images attach

Nice and clean, I couldn't read my tag as it was covered in mud. Save some $ and return the heat gun. If you're careful, a torch will do the same and get it way hotter. I used MAP/propane briefly (10-15 seconds), and it got super hot. Just don't let it start smoking! Yours still looks square enough; I'd try the square style extractor. Grind the end off so it's about the same dimensions of the hole you have (a touch bigger), pound it in (measure how deep your hole is first and make sure it goes in all the way). Get the outside (case) real hot. Torque it, but stop if you feel it stripping. You'll have one shot before stripping it, make it count.

 

[eldplanko]

Anyone know where to get the square style extractor that has a nut that slips over the end (i.e. turn it with a wrench or socket instead of a tap handle)?

 

[SCOTTYINWV]

A chisel won't do very good unless it has something to catch on. If you get the notch onto the outside as car possible towards the threads, it will apply the most torque to the threads themselves instead on spreading out through the plug.