gearbox inner cover nuts

[maylar]

There are 7 nuts holding the inner cover on and it seems that the lower left nut (outside the case) doesn't have enough clearance to the cover to fit a 14 Whit socket or box wrench on. My sockets are pretty thin walled and the wrench has already been ground to get at the #2 cylinder head nut.

Anybody here take a Dremel to the case and add a bit more clearance?

 

[swooshdave]

Do you have an open ended wrench? Crescent wrench?

 

[dynodave]

My 1/4W wrenches measure up like this:
Elora .822"unmodified
snap-on .776" unmodified
Brittool ground down to .714"
Gordon tool ground down to .706" need this one for some atlas rear head nuts
Snap-On (labeled 5/16BS) WTM100 6 point 1/4 drive socket .6995" unmodified, So far, has always worked on gearbox nuts

 

[850commando]

There are 7 nuts holding the inner cover on and it seems that the lower left nut (outside the case) doesn't have enough clearance to the cover to fit a 14 Whit socket or box wrench on. My sockets are pretty thin walled and the wrench has already been ground to get at the #2 cylinder head nut.

Anybody here take a Dremel to the case and add a bit more clearance?

i just use the 1/4W openend wrench on this one

 

[B+Bogus]

RGM sell small hex stainless nuts which use a 7/16" AF or 3/16" BSW spanner size.

 

[dynodave]

RGM sell small hex stainless nuts which use a 7/16" AF or 3/16" BSW spanner size.

Is every Norton AMC gearbox in the world "broken" and has to be fixed with RGM nuts? Having a proper box end or socket (with torque wrench) seems a better solution to me...

 

[L.A.B.]

Some Commando inner cover nuts supposedly had small hexagon (3/16" BSW) nuts according to the late John Hudson and my Mk3 does.

 

[dynodave]

LAB
Just to clarify...you show the only nut, except the OP subject nut that can be wrenched with a wrench! The 5 on the inside are all better if socket accessible and it would (IMO) be foolish to open end wrench any of them needing such a steep angle to get the wrench on.
The OP nut is the next one CW from your pix, and I'd agree with him it is one of the 2 tightest clearance/access nuts of the 7.
FWIW it would seem the Canadian, Connecticut and my 2 MKIII gearboxes (including the 5 mile MKIII) are all 1/4W.
Also FWIW all of mine came originally with outer cheese head slotted screws not allen screws.

Starting after next weekend is our national rally and I'll try, with a few hundred bikes there, I'll try to do a survey of gearbox nut sizes. LOL

 

[L.A.B.]

Just to clarify...you show the only nut,

All are small hexagon.

 

[L.A.B.]

Whilst the possibility the nuts have been changed can't be completely ruled out, it seems unlikely anyone would take the trouble to change the inner nuts just for the sake of it.

 

[L.A.B.]

The 5 on the inside are all better if socket accessible and it would (IMO) be foolish to open end wrench any of them needing such a steep angle to get the wrench on.

I don't think anyone suggested using an open end on the inner nuts. Only the outer nuts if a suitably thin socket wasn't available.

 

[dynodave]

full quote please

you show the only nut, except the OP subject nut that can be wrenched with a wrench! The 5 on the inside are all better if socket accessible and it would (IMO) be foolish to open end wrench any of them needing such a steep angle to get the wrench on.

full quote please
Yes admittedly the wrench sits on the nut. Open end wrench as a screwdriver on either 1/4W or 3/16W? 12ft/lb?
Not my cup of tea for good mechanics.

Just found my (unmodified) 3/8 drive Japanese 5/16BS Koken deep socket at .701" OD. Works fine on the 650 manxman.
Got both koken socket sets from BCS. regular & deep

 

[L.A.B.]

full quote please

Doesn't seem to change anything?

What do you actually mean by?..

you show the only nut, except the OP subject nut that can be wrenched with a wrench!

Yes admittedly the wrench sits on the nut. Open end wrench as a screwdriver on either 1/4W or 3/16W? 12ft/lb?

Still at a loss what you mean? My photo of the 3/16W spanner merely demonstrates the internal nut hexagon is 3/16W not 1/4W.

 

[dynodave]

No arguement that a 3/16 won't work...even on all 7
What's my point
Simple
2 outside nuts are easy for slim box wrench
Socket is king in this 7 nut situation.
Can you put a regular angle box wrench in a useful fashion on any of the inside nuts of an assembled box. 3/16 or 1/4
Deep offset box would not be much better.
Open end used as screwdriver on all 7 ? More swing on the 3/16 yes but even less swing on the majority of boxes having 1/4W.
Not my style...and I hate to wreck hardware.

 

[dynodave]

Not my style...and I hate to wreck hardware.

This comes from so much of my norton work to undo the damaged hardware carnage of unskilled or uneducated previous owners & mechanics.

 

[L.A.B.]

No arguement that a 3/16 won't work...even on all 7

It will on mine. The photos were only to demonstrate my Mk3 has 3/16W hexagon nuts.

I wasn't suggesting a 3/16W spanner would fit a 1/4W nut if that's what you thought, otherwise I still don't understand what you are getting at.

Can you put a regular angle box wrench in a useful fashion on any of the inside nuts of an assembled box. 3/16 or 1/4

Open end used as screwdriver on all 7 ? More swing on the 3/16 yes but even less swing on the majority of boxes having 1/4W.

I wasn't suggesting anyone should do that!

I think you have simply misunderstood? My only intention of posting the photos was only to show both the outer and inner nuts on my Mk3 are 3/16W hexagon.

 

[B+Bogus]

Sorry I mentioned the 3/16" BSW nuts now...

 

[maylar]

Well, all the nuts on my gearbox are 1/4 Whit. That particular one is the only one that I can't get to with a socket. The bike is up on a lift right now and the center stand gets in the way of using an open end wrench. I'll have to put the Norton on the stand to tighten that one. My socket is already ground pretty thin and I don't want to break it.

I wonder what the factory used to tighten that one?

 

[Deets55]

Mine is:
5/16” BS 1/4” W
Kokon regular length socket w/ .705” OD fits the 2 lower outside inner case nuts with no interference issues

 

[dynodave]

Sorry I mentioned the 3/16" BSW nuts now...

Don't feel bad, no real harm.
Except for John Hudson declaration which in all likelyhood is true about the smaller nuts on some bikes...It's not what the book shows.
Is the reduced hex 3/16/standard height even used anywhere on any or all series of commado? ... nothing comes to mind.
Atlas alternator? atlas timing chain tensioner hold down. Other featherbed uses?

However from a different perspective here in the USA, getting Brit spec hardware is slower and more difficult and expensive to get. Finding correct fitting wrench/tools is just as much a challenge.