750 rear head nut wench?

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seaguy

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removing the 750 commando rear head nut on my engine is starting to look impossible. I ground down a 5/8 box to almost nothing to find it was too loose . I am wondering if there is a special wrench to buy for this one. Any suggestions?
 
It's a 1/4 Whitworth. I dunno the decimal size but it's close to 14mm. You will need to grind the box side of the wrench for clearance to the cylinders. The other 3/8 bolts and nuts in the head are the same size. Every Commando owner should have a set of Whitworth open end / box wrenches and sockets. They usually come in sets of 5 sizes, and are available from any of the Brit Iron parts vendors.

If you find anyone selling individual wrenches, let me know here please. I want to make a 1/4 Whit extension for my torque wrench so I can tighten that #2 nut correctly.
 
maylar said:
It's a 1/4 Whitworth. I dunno the decimal size but it's close to 14mm. You will need to grind the box side of the wrench for clearance to the cylinders. The other 3/8 bolts and nuts in the head are the same size. Every Commando owner should have a set of Whitworth open end / box wrenches and sockets. They usually come in sets of 5 sizes, and are available from any of the Brit Iron parts vendors.

If you find anyone selling individual wrenches, let me know here please. I want to make a 1/4 Whit extension for my torque wrench so I can tighten that #2 nut correctly.
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Maylar, I believe British Tools and fasteners sells cheaper Whitworh wrenches seperately.
 
This probably won't help but I use an old Triumph barrel nut spanner (wrench). If you can find one it fits the rear head stud nut, front barrel base outers and sleeve nuts (on an 850 style barrel). Doesn't work on the rear barrel base nuts It's a 12 point but works fine on hex heads. Only 4.5" centres so it needs some muscle for the rear nut.
750 rear head nut wench?
 
Maybe this place? Looks like they sell separate pieces.

I have not ordered from them before.

Samstag Sales

Maybe something like this:
750 rear head nut wench?


or this might work?
750 rear head nut wench?
 
Maybe it's the 2BA. Mine is a loose 14 or a tight 15mm. Checked every written source I could find and none mentioned the #2 nut's wrench size.
 
seaguy said:
Maybe it's the 2BA. Mine is a loose 14 or a tight 15mm. Checked every written source I could find and none mentioned the #2 nut's wrench size.
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As maylar said, the rear nut hexagon size is 1/4 Whitworth (or 5/16 BSF) = 0.525"

http://www.sat.dundee.ac.uk/~psc/spanner_jaw.html

A 14mm spanner/wrench should be slightly loose in it and a 15mm very loose?

Certainy not a 2BA = 8.23mm = 0.324" - hexagon.
 
Unless someone replaced it with something non-factory, it's 1/4W. Same size as the 4 bolts near the spark plug holes, and the 2 nuts and 1 bolt at the front of the head. The studs are 3/8-26 if someone replaced that one with 3/8-24 it could be a 9/16 SAE size but getting a wrench on it would be tough.
 
I own a set of Metrench sockets and spanners. Ive found these to be very useful in removing odd ball nuts and bolts and invaluable in the removing of butcherd or rounded off nuts etc. These actually work well on Jap or Brit bikes etc etc as they grip the walls and not corners.
rgds Foxy
 
Foxy said:
I own a set of Metrench sockets and spanners. Ive found these to be very useful in removing odd ball nuts and bolts and invaluable in the removing of butcherd or rounded off nuts etc. These actually work well on Jap or Brit bikes etc etc as they grip the walls and not corners.
rgds Foxy
Click to expand...

I have these too. Like them a lot.
 
Sorry, got the loose/tight thing goofed up. Must be something other than the correct size nut because its wrench size is larger than any size on the head. A 15mm is snug. Think I'll grind up a 15mm box to fit. Is Whitworth and BA two different brands? Thought 1/4 whitworth ment 1/4" square drive. Guess i need to google "Her Magisty's wrenches" and learn something. There is barely a 1/16" inch behind that #2 nut. May wind up making a thin wall line wrench to get one on it. Once I get the head off the fun begins. There is one wrung off spark plug to extract. Oh yeah. threads about an inch long :?
 
seaguy said:
Whitworth and BA two different brands? Thought 1/4 whitworth ment 1/4" square drive.
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BSW, BSF, BSP CEI, BSCy, BA etc., are types of British standard screw threads commonly found on British motorcycles, they are not brand names (OK, "Whitworth" was originally, I think?) . Many threads were changed to American Unified (UNF & UNC) threads on later model Commandos.

http://en.wikipedia.org/wiki/British_Standard_Whitworth
http://www.timebus.co.uk/rlh/whitworth.htm
http://www.britishfasteners.com/threads/bsc.html
 
Should I admit to this? :roll:
In a pinch, I have used a 14mm boxed end wedged at an up/down angle.
Of course for reassembly I used the proper 1/4" whit and a new nut. :wink:
 
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