NOS crankshaft

What's the consensus on replacing bolts/nuts/studs on an unused crank after cleaning? Bolts and studs ok to re-use if they pass a stretch measurement and replace the nuts?

Anybody have the bolt and stud tolerance? None of my manuals seem to have it.

Good or bad sources for such important little parts?

Thanks!

does anyone have any input on this?
triumph mechanics prefer replacing all nuts and bolts on their three piece crankshafts, and i've heard some norton folks say only nuts if the bolts and studs check out, but how does all this correspond to a nos crank? anyone?

It may be a little hard to get someone to reply as it's almost like an oil thread, lots of people will tell you they have used old hardware for years and never had a problem. Some say just change the nuts, some may say change bolts and nuts. Some say the bolts and nuts they make now are not as good as the old ones, so it's better to use ones that are already tested true. I'm in the camp of those that think if you are going to run your bike hard and rev it high then you should change the hardware on the crank and rods. If it's just a daily rider I think you may get away with just changing nuts? I really don't have enough knowledge to say one way or the other, but as a kid in high school auto shop our teacher always said to replace rod bolts.

If the crank is genuinely unused, re use them I say.

I'm with Fast Eddie. If they are unused, they haven't had any load cycles to degrade them. Sitting on the shelf doesn't stress the crankshaft much. If you were going to hop it up and race it, I'd suggest maybe reaming the holes out for the larger MK3 studs, as well as the other trick stuff, like radiusing the drive side corner, making a steel flywheel, and shot peening everything, but that's serious overkill for a street bike.

Ken

lcrken said:

I'm with Fast Eddie. If they are unused, they haven't had any load cycles to degrade them. Sitting on the shelf doesn't stress the crankshaft much. If you were going to hop it up and race it, I'd suggest maybe reaming the holes out for the larger MK3 studs, as well as the other trick stuff, like radiusing the drive side corner, making a steel flywheel, and shot peening everything, but that's serious overkill for a street bike.

Ken

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yes. probably overkill. it's only an 88ss.

Where in the world do you get an unused 88SS crank shaft?

Bernhard said:

Where in the world do you get an unused 88SS crank shaft?

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thank goodness, there are secrets left in the world.

i've got two, one of which may be available if there are any interesting trades out there.