Quote:
Originally Posted by rich weyand
The issue with using grade 5 and grade 8 bolts is one of torque specs. You need to torque bolts to where they deform a bit in order for them to stay tight. To do that with grade 5 and especially grade 8 bolts requires that they be torqued much more.
From this chart, a 7/16-14 (which is 7/16 NC) in grade 2 takes 24 ftlbs, in grade 5 takes 37 ftlbs, and in grade 8 takes 52 ftlbs of torque to be considered torqued up. The question then is, what kind of threads are you torquing it into, and can they take that?
It's not just a simple issue of "more is better".
https://www.boltdepot.com/fastener-i...ed-Torque.aspx |
Quote:
Originally Posted by 65 C20
Captain Fab has been making and selling power steering brackets for years and supplies grade 8 bolts in his kits.
I am just saying.
You say you have already had one break, why go with cheaper bolts ?
|
Boy... Folks don't listen do they.
It's not a question of cheaper or more expensive... or even Mores' law.
The threads in the Cast Iron steering box may not put up with the torque necessary to properly tighten Grade 8 bolts.
__________________
1959 M35A2 LDT465-1D SOLD
1967 Dodge W200 B383, NP420/NP201 SOLD
1969 Dodge Polara 500 B383, A833 SOLD
1972 Ford F250 FE390, NP435/NP205 SOLD
1976 Chevy K20, 6.5L, NV4500/NP208 SOLD
1986 M1008 CUCV SOLD
2000 GMC C2500, TD6.5L, NV4500
2005 Chevy Silverado LS 2500HD 6.0L 4L80E/NP263
2009 Impala SS LS4 V8
RTFM... GM Parts Books, GM Schematics, GM service manuals, and GM training materials...
Please include at least the year and model in your threads. It'll be easier to answer your questions.
And please let us know if and how your repairs were successful.