3 head bolts/nuts front n' center

L.A.B.

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I‘m sure you have these in the colonies, and I’m intrigued as to what you call them!
= Tube or tubular box wrench.

What we in the UK call a ring spanner is a 'box wrench' in the US.
 
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Yes, they get rusty due to the heat in that vicinity.

Use a 6-point socket, 1/4" drive. They have thinner walls. work to get the best fit between the nearest sizes of various type. As long as it's 6-point you WILL get one to fit well enough to torque down, even if you have to tap it over the rust.

Is there a possibility that the previous owner cross-threaded some incorrect nuts down on there?
Yes the nuts look fine with the flashlight and not cross threaded or angled at all. They are not completely down over the studs though. My Gordon is a 6 pt. and the King Dick a 12.
 
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I have a front barrel stud here in my hand, 5/16 -26 both ends.
I screw on 3 different nuts regular form .525, reduced hex .444, and to my shock, a third @ .500 :confused:
 
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I have a front barrel stud here in my hand, 5/16 -26 both ends.
I screw on 3 different nuts regular form .525, reduced hex .444, and to my shock, a third @ .500 :confused:
Thanks Dave. This could be the real problem. Studs and nuts not matching as they should.
 
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I have a front barrel stud here in my hand, 5/16 -26 both ends.
I screw on 3 different nuts regular form .525, reduced hex .444, and to my shock, a third @ .500 :confused:
I had the same thing recently on a 68 Atlas motor. None of the usual sockets fit and to my surprise a 1/2" one slipped right on !!
 
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I had the same thing recently on a 68 Atlas motor. None of the usual sockets fit and to my surprise a 1/2" one slipped right on !!
About to try that. I'm about to grind down the outer of the 1/2 to make it slimmer and drop down into place.
 
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The proper 3/8D 5/16BS/1/4W Koken =.704 dia
My craftsman 3/8D 1/2" 6point/deep =.723" dia also fits just fine in all 3 front holes clear to the bottom
 
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If it in fact it is 1/2, then the first ting to do is to identify the nut thread and if some idiot custom made a cylinder repair stud, helicoiled the barrels in UN threads along with a 5/16-24 UN nut!
good luck
 
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If it in fact it is 1/2, then the first ting to do is to identify the nut thread and if some idiot custom made a cylinder repair stud, helicoiled the barrels in UN threads along with a 5/16-24 UN nut!
good luck
Thanks Dave , I think you are on the money with this problem. Today I bought 2 sockets. 1/2 inch deep thin walled as suggested in earlier replies.
3/8 and 1/4 " drives. No luck. Too small to fit over the 2 recessed nuts in Question. In desperation I Dremel tool grinder tip stone ground away socket internal edges to attempt any kind of a drop down into. No luck. Now I'm thinking getting some plasticene or play dough or artist craft soft form material to press down into one of the bores and over the nut to make a soft cast then pull up by string for measurement. Very little rust involved , nuts seem clean. WD 40 is now in there. I'm no longer trying to torque down but to remove the 2 problem size nuts to correct back to stock. 76 MK 111.
 

grandpaul

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Like I said, go to a 6-point socket that you have on hand that is slightly larger and try that...

Use calipers to see if that'll be a metric, SAE, or Whitworth that is JUST slightly larger...
 
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GP it both has to fit IN THE HOLE and OVER THE NUT.

"T"
1/2 .500"/
13mm .511"/
1/4W 5/16BS .525"/
14mm .5512"/
9/16 .5625" thin wall 6 point 1/4 drive
all sockets fit in the hole to the bottom

something has to work if it's a hex head bolt. An allen head bolt will be your demise LOL
You should LOOK super close to see if it is a hex head that has been deformed by an inappropriate over size socket that has boogered the hex corners. then you would need to hammer the original proper socket on through the extension.
Just think of the prior rocket scientist (idiot) that put the 5/16 BS on with a 14mm socket. How many times have you heard and cringed at those guys that use ANY metric tool on a norton.
A significant part of my working on nortons is fixing prior screw-ups. They are obviously worth less....just like powder coating :mad:
 

SteveA

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I have never had a problem with these nuts on the 5/16" studs!

Way back I used a tubular 'box' spanner. but not for long before I got 3/8" square drive tools to fit.

The only thing 'special' I use is a 5" 3/8" square drive extension bar instead of a 6" when the motor is in the frame, for better clearance!

Standard 3/8" square drive size socket!

Currently mine are fitted with ARP style nuts and matching studs from CNW.
 
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Yes I will order in the ARP kit with my MK 111 starter train upgrade shortly once tested thoroughly. And I hope this includes cold temps.
 
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