differential fill plugs glued shut

[maxpanic]

So I finally got around to doing the initial fluid checks and replacement as needed for my M109 that I bought last fall, turns out the differential plugs are all glued shut.

First I tried my 1/2 inch socket wrench with extension and couldn't get them to budge at all

I tried an impact gun with a 1/2 inch extension and it still just sits there a laughs at me and says "Idiot, you shouldn't have bought me." After all, my list never had the check the differential fill plugs to see if they open. It does now! I got no idea what kind of glue it is but the stuff works and I can see it sticking out of the sides of the plug so I know there is some kind of hard stuff there. seems like JB weld or something.

So now I am pondering a solution and would like the advice of the experts. should I try drilling them out and tap another thread? perhaps 1/2 inch hole in the cap and a 1/2 inch pipe fitting for a plug? Definitely not one of my better ideas. So what do I do?

 

[hndrsonj]

Got a pic of the glue sticking out? I'd find it really hard to believe someone JB-Welded it in there. You might be best off welding a nut on the plug.

 

[DieselBob]

Have you tried heating them and then a couple of good sharp raps with a hammer to break loose the sealant.

 

[91W350]

I am betting it is dried and hard lube you are seeing. We have been fighting a few plugs around here, trying to drain the five tons headed to the shredder. We found two guys working together really helps. Get good solid pressure on the plug with a breaker bar and then have your partner try to drive the half inch square through the bottom of the pumpkin. A couple of really solid love taps seems to do wonders. Glen

 

[gimpyrobb]

Yup, if its a thread-lock, hit it with heat!

 

[m16ty]

I'm saying it's some sort of sealer. Most thread sealers are supposed to remain soft but if left on for a long time it will get hard.

I think the actual size is 9/16". Most of the time a 1/2" ratchet or breaker bar will work but be sure not to strip out the hole or it will be even harder to get out.

 

[Flyingvan911]

Some heat will help burn that stuff out of there. I apply a drop or two of oil to the threads of the plugs when I put them back in. Just a little bit will help keep it from getting stuck.

 

[Beerslayer]

Some heat will help burn that stuff out of there. I apply a drop or two of oil to the threads of the plugs when I put them back in. Just a little bit will help keep it from getting stuck.

What You ^^ Said.

Put some heat on the plug. Hit it with a hammer. Try again.

I have a practice that I have adopted from working on heavy equipment for many years.

It goes together with either Red Loctite or Antisieze.

 

[houdel]

Prolly some old-timey thread sealer. I remember some stuff from back in the day that was a dark brown, gooey, varnishey looking stuff that would clump up right where the plug meets the diff case and dry out hard as a rock. Heat and beat as suggested. Sometimes trying to tighten first then loosen helps to break it loose.

 

[Heavysteven]

I found a non racheting 1/2 drive works best. I bought one from Sears and it fits the square plug tight. That drive and a hammer did the job for me. All my other 1/2 ratchets and extensions are round at the ends.

 

[Tow4]

+2 or 3 with the heat. Put the ox act torch with a cutting or rosebud tip (lots of heat to heat the plug only) right on the plug. Once it changes color a little you should be able to get it off. Don't heat it long enough to burn the truck down, it doesn't need to be glowing.

 

[zout]

Here's a good guess.

Someone had been using air impacts on them plugs and that is a no no.
They do not have to on with the grip of god.

After probably so many times of screwing up the threads in the diff they would not seal any more or stipped so they had nothing else to put in the hole or how to fix them.

So they mixed up a big heaping GOB of JB Weld and jamed them in there and held them till it dried.

I like guess's.

 

[Heath_h49008]

Just heat it gently and if you have to try a HAND impact with a medium hammer. Even if it's JB weld, they will come free. Gentle heat and a chunk of dry ice from the grocery store can do wonders when you heat the boss and cool the plug/bolt.

 

[misupratwin]

I been a auto tech for close to 20 years, The one of the best method i have found is to heat and cool with a jug of water, heath-h49008 way is even better (dry ice)
You wouldn't beleive the rusted exhaust nuts and studs you can remove this way, without breaking them.

 

[Heath_h49008]

We used to actually use waste freon... just a squirt from the liquid line. Not the best practice, and I doubt he has a recovery machine sitting there.

Alternate sources of near cryogenic liquid: Canned air for use in cleaning keyboards (turn the can upside down), freon cans, dry ice chunks, I think it's "Gunk" brand "Freeze off" penetrating oil.

Almost anything will do the trick... even just good old PB Blaster... even though it stinks like heck.

 

[135gmc]

Just about any sealant, from Permatex to pipe dope to epoxy to Loctite, will surrender with heat. It shouldn'y take more than about 350-400 F to soften it. Like someone said earlier, if all else fails, weld a nut to the plug - the heat from the welding will loosen it up.

 

[45FMJoe]

Breaker bars are also invaluable tools in these cases. Lots of extra leverage with little effort.

 

[jwaller]

ya it's prob indian head sealer. that stuff dries to a concrete like hardness and takes a chisel to get off but makes a seal like no other.