Norton Crank reassembly torque procedure

p400

p400

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I didnt look real hard in forum, but I have a question on tools and torque on reassembling the seven studs and nuts on a Mk3 crank.

How is the crank held and exactly what tools are used .


20240120_Mk3CrankTorque1.jpg
 
You need to hold the crank in a vice.

Then you can get clever with torque wrenches and crows foot attachments etc.

Sadly some hammer wielding Neanderthal‘s still do it as shown in the Mick Hemmings video and simply use two good wrenches (spanners).

This is not as heinous as some believe it to be, a short practice tightening up some nuts by hand, and checking the torque with a torque wrench, and you find you can be surprisingly accurate.
 
I've rebuilt 4 Commando engines and never found any sludge in the trap to speak of. The Commando trap is huge compared to a Triumph or BSA.
 
Fast Eddie said:
You need to hold the crank in a vice.

Then you can get clever with torque wrenches and crows foot attachments etc.

Sadly some hammer wielding Neanderthal‘s still do it as shown in the Mick Hemmings video and simply use two good wrenches (spanners).

This is not as heinous as some believe it to be, a short practice tightening up some nuts by hand, and checking the torque with a torque wrench, and you find you can be surprisingly accurate.
Click to expand...
Oh dear, I am that Neanderthal!

But I do put tape around those big ends to prevent spanner mishaps doing damage!
 
Am usually a Neanderthal but not when I did my engine some time back.
Have seen Mick Hemmings video on engine rebuild I realised there was a very simple way to do the crank that would not have me worrying about it as the rev counter needle swept ever closer to the red bit of the dial.

I got Mick to do it. 😄

Such a shame that he is no longer with us as he did a wonderful job and I never worry about bottom end no matter what the rev counter say.
 
Fast Eddie said:
You need to hold the crank in a vice.

Then you can get clever with torque wrenches and crows foot attachments etc.

Sadly some hammer wielding Neanderthal‘s still do it as shown in the Mick Hemmings video and simply use two good wrenches (spanners).

This is not as heinous as some believe it to be, a short practice tightening up some nuts by hand, and checking the torque with a torque wrench, and you find you can be surprisingly accurate.
Click to expand...
How many would be careful (or clever) enough to compensate torque wrench readings with the crows foot or other contortions needed to actually gat an accurate reading anyway?
 
p400 said:
I didnt look real hard in forum, but I have a question on tools and torque on reassembling the seven studs and nuts on a Mk3 crank.

How is the crank held and exactly what tools are used .


View attachment 112190
Click to expand...
www.motosport.com

Motion Pro Adjustable Torque Wrench Adapter

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Amazon product ASIN B001GS0ZBY
Several choices. So easy.
 
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MikeG said:
How many would be careful (or clever) enough to compensate torque wrench readings with the crows foot or other contortions needed to actually gat an accurate reading anyway?
Click to expand...
If the crow's foot is at 90 degrees to the shaft of the torque wrench, then the torque setting is unchanged. Seems odd, but true.
 
If you put two crows feet together, indexed at 180 degrees, I bet the torque reading is unchanged. :)
 
Thanks for advising here.
What I did to satisfy myself on torqueing the seven nutted studs with Loctite 243 was to purchase a couple of tools at Harbor freight.
The new 3/8 breaker bar ($30) was long enough to match my torque wrench length so I could keep the crank stable in the vise.
Set of crows feet to get another 9/16" ($14)
Using two crowsfeet I easily torqued the 14 nuts.

20240122_171321.jpg20240122_173626.jpg20240122_173908.jpg

First at each nut pair you apply Loctite and tighten with standard 6" hand wrenches as tight as you can.
Then you come back with crowfeet and apply torque as required 25-30 ftlbs.
 
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MikeG said:
How many would be careful (or clever) enough to compensate torque wrench readings with the crows foot or other contortions needed to actually gat an accurate reading anyway?
Click to expand...
Engage them at 90 degrees to the wrench and no need for adjustment.

www.tekton.com

How to Use a Torque Wrench with a Crowfoot Wrench | TEKTON

Learn how to accurately use a torque wrench with a crowfoot wrench to measure torque. Use the included Torque Conversion Calculator.
www.tekton.com www.tekton.com
 
This book has been in my toolbox since my father gave it to my many years ago. Never paid much attention to it as I'm not building aircraft.
 
I worked at a car assembly plant during my engineering study for 6 months every year back in the early 80's. First job was to accompany the process engineer to pick up all the newly introduced torque wrenches from the assembly line for recalibration. This was being done on a daily basis as they would not stay calibrated, after 20 odd hours the quality checks showed the bolt torques were drifting out of acceptable range.

So early on the old human arm was a better torque wrench, and that old one you have on your bench will probably have been never checked since you bought it. Hence why I have an old beam torque wrench to calibrate my newer click torque wrench's.
 
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