panhandler1956

panhandler1956

Well Known Member
I'm converting an IO-360-A1A from fixed pitch back to constant speed. Among the myriad of issues I have ran into, this latest one has me spooked.
There is a fitting on the nose of the crankcase that is now occupied by a plug, but needs to have a steel 90 degree fitting for the stainless steel oil line that runs from the governor. This plug is very very stuck! I have tried soaking it in liquid wrench, taping on it in various ways, different versions of the 1/4" allen wrench to engage what is left of the teeth and nothing is moving it.
I am considering using a large size easy-out that will engage just the inside the hex slot as I don't want to drill it for fear of getting metal inside my crankcase - any sage advice before I do some real damage?:eek:

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Heat

A few years ago I had the same problem on my O-320. An experienced mechanic applied heat with a micro torch arround the plug and it broke loose easily.
 
Piece of cake. First don't go near it with a torch. Get the "easy out" and the appropriate size drill bit.

However, be very careful and take your time with the easy out. They are fragile and if you break one in the case you're in a heep of doo doo. They work great though and you won't have any troubles. Use the biggest size (maybe 3/16 or 1/4). That plug is soft and will come right out.

Don't drill clear through the plug. You shouldn't have to. Drill just a few hundreths at a time until the easy "grabs". I would use a heavy grease on the bit for any chips to cling to just in case you go through. Use a vaccum while you drill that helps also.
 
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I've got no experience with Lycomings but I've never had much luck keeping easy outs from snapping. I'd also be worried about drilling into the case and sending chips in there. One thing that's worked well for me is lightly pounding a slightly oversized torx bit into the plug and the using an impact screwdriver (the kind you whack with a hammer). Obviously you don't wanna hit too hard.
 
Stuck Plug

Recommend you check with your local engine overhaul shop. They deal with this type of problem every day. Conventional wisdom is to heat the area around the plug to expand the crancase, which should allow you to remove the plug.. Good luck..
 
I have had a lot better luck with this type of extractor

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than this type.

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You can control the depth with a washer if needed----and thus the amount of bell mouth in the stuck part.

I doubt if penetrating oil will do any good, the plug is more than likely installed with a thread sealer. to prevent leaks.

If you use the top style extractor, gently turn it into the part until it starts to grab, then keep a little torque on it, and tap it in with a hammer so it continues to turn in until the shoulder seats.

Then, put some muscle in it, and tap with a hammer to jar the threads into releasing.

Dont hammer the wrench to turn it, you are hammering the extractor like it is a nail being driven into the case. Gently of course. Or, rivet gun set on low pressure may help.

Good luck
 
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Probably a dumb question so I apologize ahead of time... but couldn't you weld something to the head of the plug? Like an oversized allen wrench or something that fits just inside where the teeth are worn our? Weld it in place, then just unscrew as normal?
 
Heat it up, it will not only soften the sealant on it, but the aluminum case will expand faster than the steel plug. Not smoking hot, but a couple of hundred degrees, your not going to hurt anything, heck, the oil inside is that hot under use. Another trick to try is try a metric allen, some are just a little bigger than the fractional sizes and can take up the extra slop. Buy a cheap one at sears and grind it down untill its a snug fit then tap it in with a hammer.
 
Heat applied to the case with a heat gun, and a good quality allen socket in a long breaker bar is the proper process (I would strongly discourage you from doing anything involving drilling other than just the depth of the hex cavity, if you are not intending to disassemble the engine).
Now that the plug is damaged, the tool Mike posted is probably the best choice.
You will still need to apply heat with a heat gun.
 
Heat around it with a heat gun or hit it with this stuff and it will help a bunch. This stuff stinks (smells bad) but it sure does loosen parts!!!

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I've pulled lots of these "stuck" pipe plugs. Heat gun might be enough or go to a propane torch (you might burn paint, so what). You need to soften the pipe sealant or you might break something (your knuckle). It'll come right out if you heat enough. I've seen a case get cracked by just torquing on it with a breaker bar. That old pipe dope gets so hard I've seen fittings twist right off a case. Worst one is usually the breather fitting, sometimes they don't get removed for several overhaul cycles.
 
Easy outs don't work very well. They are typically cast and as a result are weaker. The other thing going against them is as they screw into the damaged part they tighten up the screw you're trying to remove. A better tool is one of these:

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I've had these work in instances where easy-outs didn't work. Tap it in with a hammer and away you go. All of mine are home made out of pieces of HSS lathe toolbits...just grind to whatever shape and size you need.

Also 50/50 mix of acetone and ATF works far better than Kroil as a penetrant, but generally penetrant oils have no effect on pipe threads since by design they seal.
 
Been there done that a couple of times. As others have mentioned, use heat and a strong tool to apply torque as necessary. Work the temp up as you are twisting. I'd say I got up to 300F before they came loose. I used a propane torch. Wear safety glasses in case something comes apart. Hard to get solvent into the threads, but you can try. I never had to.
 
It worked!

All,
Thanks again for the great advice. I got an extractor today that would engage the inside of the 1/4" hex slot. I put the heat gun on for 2 minutes and it just wasn't heating it up. I grabbed the little MAPP gas torch and hit it for about :30 seconds. The extractor cranked into the fitting nice and snug and with alittle help from a cheater bar it broke free with ease!
This forum has saved my bacon again! Thanks Doug!

In this photo the fitting is already partially out. No metal in the engine, no damage to the cases.

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