Nuts & bolts 101

[patrickt]

Originally Posted by Cobra #3170

I use proper air craft grade bolts and nuts on my half shafts and have found that they do not maintain torque. I have to change them a couple of times a year. I think they may be stretching under the torque load. I did not have this problem when the car had lower power levels in the 1960's through 1990's.

Now, this is an area that is just slightly beyond my expertise, but you might consider going with a NAS 624/MS 21250 Series bolt (as per that two page PDF I just posted).

[Cobra #3170]

Originally Posted by patrickt

Now, this is an area that is just slightly beyond my expertise, but you might consider going with a NAS 624/MS 21250 Series bolt (as per that two page PDF I just posted).

Certainly worth a try, I don't look forward to changing out those 16 fasteners every 4 months during the season. Thanks for the suggestion! I had a problem with steering arm bolts failing (Grade 8 from Air Craft Spruce) and switched to aerospace grade 160,000 psi bolts and it solved the problem, might work with halfshaft too.