1975 Norton MK3 850 cam sprocket nut and LH worm gear nut torque

p400

p400

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Where is the torque value for the 15) worm gear and 24) cam sprocket nut?

Engine1a.jpg1975 Norton MK3 850 cam sprocket nut and LH worm gear nut torque
 
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Per Old Britts
Oil pump worm gear/nut (06-7889), LH thread) 15 ft lb.
Camshaft sprocket nut (06-7774) 60 to 80 ft lb depending on cam metal.

Not making much sense to have worm gear at 15 ftlb

What is the "Mainshaft nut" at 40/50 flbs in my first post?
 
p400 said:
Per Old Britts
Oil pump worm gear/nut (06-7889), LH thread) 15 ft lb.
Camshaft sprocket nut (06-7774) 60 to 80 ft lb depending on cam metal.

Not making much sense to have worm gear at 15 ftlb

What is the "Mainshaft nut" at 40/50 flbs in my first post?
Click to expand...
In both cases the shafts are "turning into" the nuts. IMHO, 60-80 ft lb is WAY too much if you have a chilled iron cam (you probably do).

For a much more detailed look at torque: https://gregmarsh.com/Mc/ViewPDF.aspx?src=NCT

Updated often, including today as I learn more.
 
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p400 said:
Per Old Britts
Oil pump worm gear/nut (06-7889), LH thread) 15 ft lb.

Not making much sense to have worm gear at 15 ftlb
Click to expand...
Friction at the worm nut from the driven gear at the oil pump shaft tries to tighten the nut, which has a left hand thread, so the nut will hardly get loose by itself. Therefore, no large pretension is required.
Besides, the worm nut itself is high and wont allow thread deformation easily (generally speaking, threads deform when torquing a nut or a bolt, or both together).

- Knut
 
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