Sparkplug Socket

kyleb

Final Approach
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Drake the Outlaw
I'm looking for a couple of 7/8" aviation plug sockets. Spruce, Sporty's, etc. have 'em for $25-$30. I think Chief's is at $37.

Where can I find the inexpensive version to live in the flyaway kit? Ideally, I'd want something with a hex fitting for a wrench and a 3/8" drive opening.
 
Where can I find the inexpensive version to live in the flyaway kit?
Any deep 7/8" socket will work provided its deep enough for the plugs you use. Especially for a fly-away kit.
 
Any deep 7/8" socket will work provided its deep enough for the plugs you use. Especially for a fly-away kit.

The problem is most sockets don't have the hex fitting that allows you to turn 'em with a wrench. There are a couple of places (typically aft top plugs) where baffles mean you can't get a ratchet handle in there to turn a socket.
 
Given how seldom one uses a spark plug socket, what about just keeping it in the kit? You’ll always know where it is and it’ll be nearby. And it’s only used on the plane, so…
 
You have to turn it with something.

HF torque wrenches weigh similar to a ratchet.

Write plug torque in obvious place also.
 
Given how seldom one uses a spark plug socket, what about just keeping it in the kit? You’ll always know where it is and it’ll be nearby. And it’s only used on the plane, so…

You're making the assumption there's only one airplane... ;-)
 
The problem is most sockets don't have the hex fitting that allows you to turn 'em with a wrench.
Have you tried a wobbly extension? I honestly never owned an aircraft spark plug socket, however, I do have several sets of Champion plug wrenches.
 
Have you tried a wobbly extension? I honestly never owned an aircraft spark plug socket, however, I do have several sets of Champion plug wrenches.

The geometry puts the baffles too close to the end of the plug. You can get a socket on the plug, but you have to lean on the baffles more than I like to get any sort of extension or ratchet on the aft plugs. So the direct answer is maybe, but I think it would be abusing the baffles.
 
So it acts like a crowfoot or flare nut wrench? no good? Seems it'd even be lighter to keep in the spares kit. :)

It would be, but if you look at where the sides grab a plug, they are way down at the end of the socket. Is that gonna distort and skip a flat at 35 (?) foot pounds?

I don't know either. ;-)
 
To be fair, I don't have that confidence level in HF's ordinary sockets either. :D
 
I'm looking for a couple of 7/8" aviation plug sockets. Spruce, Sporty's, etc. have 'em for $25-$30. I think Chief's is at $37.

Where can I find the inexpensive version to live in the flyaway kit? Ideally, I'd want something with a hex fitting for a wrench and a 3/8" drive opening.

I'd do this one, yup 32 for a socket crazy. Still worth it from my experience even in a flyawaykit. The magnet is nice.
https://www.aircraftspruce.com/catalog/topages/ATSmagSocket.php?clickkey=7011
 
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If a magnetic socket saves dropping 1 plug it then pays for itself.
 
I always thought spark plug sockets had rubber up in them. It should take a little force to put the socket on the plug and to pull it out. So it does not fall out when removing from deep in the engine(properly size hose can do the same and bends). I would go craftsman or to the jungle
 
How many can you fly at once?

The issue is the airplanes aren't parked/hangared close together. I've been swapping the fly-away kit between them. Turns out, the fly-away kit always seems to be in the wrong airplane. I'd rather just have two fly-away kits in addition to the bigger set of tools in the hangar I use for maintenance. Besides, the RV-6 kit doesn't need as much "stuff" as the one for the -10, which has jacking adapters and should probably include a couple of innertubes, since the ones for its tires are not a common size.
 
If you aren’t carrying a torque wrench, a box end wrench works well.
 
Exactly. Which is why I want a plug socket that has the external hex flats.

I think Stewartb was suggesting to use a box end instead of a socket. On my plane, a box end will work in an emergency.

Edit: my box end is offset , like Dan posted...be careful not to damage fins...snug is better than guttentight.
 
The sockets with the rubber inserts are for automotive plugs. I've never seen one with rubber for an aircraft plug.

Many 7/8" deep sockets have a shallow hex, then a small bore to accommodate the 5/8" or so bolt thread that a 7/8" hex nut fits. You need a socket with a bore large enough to fit over the sparkplug's larger body, and they can be hard to find. That oxygen sensor socket looks like it would work, and 35 ft.-lb. is not a big job. If you're shopping in a store for a socket, take an old plug along to try in it.

Box-end wrenches can collide with the cooling fins and bend them. That, you do not want. A bent fin can crack, and that crack can travel down into the head and now you have major problems. If you have to use a wrench, get an offset one:

upload_2023-1-15_10-0-15.jpeg

Now, some of those types have gentler curves that might not clear the fins so easily:

upload_2023-1-15_10-1-13.jpeg

You're better off with the older style.
 
I think Stewartb was suggesting to use a box end instead of a socket. On my plane, a box end will work in an emergency.
Yes. I need a combination wrench to hold the plug to get the cap off, so once that’s done I flip the wrench over to break the plug loose, then spin it out with my fingers. To install? Reverse the process. I’ve never needed to swap a plug away from home but if I did, I’d remove it and reinstall with anti-seize and a torque wrench once I got home.
 
Box-end wrenches can collide with the cooling fins and bend them.

All comments are spot-on. I like using a socket because it gets the wrench or ratchet handle high enough you won't <easily> dent a pushrod shroud.
 
Bending a pushrod tube or cooling fin would take some effort. Your plugs shouldn’t be torqued enough to use anywhere near that force. My tool kit has short wrenches. More often than not they’re what I use in the hangar.
 
Get a model T sparkplug wrench, and be done. But you could probably just get the socket from AS cheaper.
 
Gee, first time I needed to pull the spark plugs I grabbed a generic 7/8 deep socket and short extension out of the toolbox and a pair of open ends for the wires, never gave it any further thought.

But the hex on the back of a spark plug socket is nice for a field kit, the rubber insert is easy to knock out.
 
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