I have a gearbox filler plug with a 13mm square head that will not budge. I've tried everything I can with a 13mm spanner but it is not moving. As is always the case, the filler is in a recess and in a gap between a drive shaft and a starter motor. Nothing more persuasive than a spanner is getting on there, it has to be a socket. I just can't find a UK supplier. Do you know where I can get one from?

Is it 13mm or 1/2" ?

If you know where to find a local snap on dealer, F316 is a 1/2" 8 point socket which is intended for square drive adjusters.

They do also do pipe plug sockets, but only 6mm and 10mm, no 13mm listed. I have the 10mm one, but don't think I have anything 13mm.

Have you tried a spline drive spanner or socket? They grip square drive stuff pretty well where a bi-hex ring spanner would not.

Dave

Edit:
This might be closer to what you want:

https://www.uktools.com/koken-3415m-13-13mm-38drive-8-point-26mm-long-double-square-socket.html

[Edited on 10/7/23 by obfripper]

Do you have a 1/2 ratchet that you can remove the square drive and put the ratchet on your bolt
Graham

will a 1/2" squaredrive socket fit on it backwards?

if so, take something like a 19mm socket put it on backwards, use a short M12bolt with a nut wound on, half in the backward socket the other half in a 19mm socket on your impact gun?

It is 13mm, but that's not to say that a 1/2 socket might be a tight fit. I'll give the UK tools 8 point socket a go, thanks.

Do you have clearance for a large tap handle/holder. That will let you pull square with both hands
Like this;
https://m.media-amazon.com/images/I/51fnNcwyfaL.jpg

quote:

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Originally posted by jacko
Do you have a 1/2 ratchet that you can remove the square drive and put the ratchet on your bolt

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15mm 12point socket fits a 1/2" square (and probably a 13mm)

I can confirm that a 1/2" socket fits on backwards and that a 15mm 12 point socket fits on. I can confirm that the fill plug is not for turning. I'm going to see if I can find a bit of round tube to slip over the ratchet handle.

smart51

What vehicle / gearbox is it?

Worth finding an enthusiast forum to see if they have a trick or some tool knowledge for it?

1975 Fiat 500. The owners club gave me the 15mm 12 point socket trick, and suggested I replace the square plug for one with a hex head if / when I get it out.

The oil weeping from the drain plug seems very clean so I suspect the dealer I bought it from replaced it. I also suspect they reused the fill plug rather than spending £1.50 on a new one, so rammed it tight to stop the old seal from leaking.

The 15mm socket is not moving it and gets jammed if pushed hard. I don't want to round off the head, so I'll wait for the 8 point socket to arrive.



[Edited on 11-7-2023 by smart51]

If the half inch socket fits on backwards can I recommend that you try an impact gun or cordless drill with torque limiting.
In my experience those with even meagre torque will help after an age of them rattling away at a stuck nut/bolt.

I have used this to really good effect in preference to a single high torque event.

Four 1/2" socket extenders totalling 600mm, some mole grips and a breaker bar later and it's out. What a ball ache. Thanks all.

[Edited on 11-7-2023 by smart51]

well done.

quote:

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Originally posted by smart51
Four 1/2" socket extenders totalling 600mm, some mole grips and a breaker bar later and it's out. What a ball ache. Thanks all.

[Edited on 11-7-2023 by smart51]

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Well done and indeed an epic effort.

A photo of the tool amalgamation wouldn't go amiss - might inspire others on here

One photo as requested. Socket set for scale. I was surprised how well the clamp gripped the bar. Even though it is square, I thought it might twist off.


socket extensions

[Edited on 12-7-2023 by smart51]

Top effort & thanks for the photo.

A good bit of ingenuity never hurts!