I’ve been rebuilding my 1960 Dommie 99 crank today. I bought a bolt kit from RGM and, surprise, surprise, it doesn’t contain any bolts - it’s all studs and nuts. However, it seems to work well enough. The only thing is, I used my trusty Haynes manual to get the torque figures. They stipulate 35 foot/pounds for each fastener, so that’s what I used. Then I was ‘wandering around’ the forum archives a bit later and found an article that said the Haynes torque figure was wrong and it should be 25 ft/pound, not 35. Will it be safe to undo the nuts on the studs and re- torque to 25 or have I now over-stretched and wrecked the studs?
Opinions please.
Thanks
Tony
Take one stud out and check…
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Thanks John. I followed your…
Thanks John. I followed your suggestion and removed one of the studs. The threads look fine and there’s no sign of any deformation to the thread or the shank. Looks like I might have got away with it.
Thanks again for your reply.
Regards
Tony
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Good to hear, I don't think…
Good to hear, I don't think 35 vs 25 gets you into the plastic deformation of the fixings, what could do is the threshing of the whip like crank behaviour at revs when the fixings are at 35.
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Take one stud out and check the thread TPI is still correct, you should be ok as the engine has not run. I took a 750 crank apart and found the TPI was stretched and a new nut would not go on. Not the first Haynes blunder or the last.