Over-Torqued Rod Bolt

[alphie]

In assembling my crank I followed Wayne's method of 15lbs/foot + 90 degrees. All worked out fine except my first bolt/nut. I ended up going slightly over the 90 +/- 2 degree.

Not feeling comfortable with that I picked up 2 more bolts and nuts for that rod. Question I have is, should I remove BOTH bolts and nuts for that rod or can I just replace the one I overtorqued?

[MBEngineering]

HI you already have doubt in your mind about the bolts, so change both bolts, which is why you got 2.

regards mike

[Eagledriver]

Did you measure the torque as you hit 90 degrees? My Bruce Anderson book gives a range of values for this torque. I've found that as you approach the high end of the range the nut turns much less per added pound which I interpret to mean I've reached the correct torque. I think the best method is to measure the stretch but if you don't do that I'd like to at least know what the final torque is. I guess the 90 degree think is to get an approximate stretch. Is there a range of allowable stretch?

My personal opinion is that people tend to undertorque these bolts. The ones I've used a stretch guage on took quite abit more torque than specified to reach the stretch number.

-Andy

[Asjac]

Where do you normally find these stretch values?

[mattr_914]

The stretch value should be included with the rod bolts. Every bolt package I've opened from ARP or Pioneer has a little spec sheet with the bolt stretch included.