The original discussion of this thread was whether to use the longer
bolt in the back or front (it goes in the back). I mentioned that I used
Grade 8 bolts and that seemed to kick off an interesting but not that
important discussion of grade, and length issues. There have been no
documented failures of the fasteners. The tubenut welds and frame interface
are the failure mode of the frame to cross member interface, not the bolts.
Bolts are important, but they are not the failure mode of this interface nor
are they known to be a significant problem.
Tom Hall published an excellent tech tip on this in January 2000
(included in your STOA Tiger Tracks newsletter), on how
to identify the failure and how to repair it. Its worth a read. It includes
superb photos of the frame inside (99% of us will never see there) and how the
tubenuts are welded to the frame rails. The front tubenut attachment is the
primary failure
due to loading and frame design in that area.
Curtis Fisher
the discussions of grade, sources, manufacturing, and tapping are interesting
-------------- the Original message --------------
> I have noticed that the bolts attaching my front crossmember/subframe appear
> to be different lengths (as it appears still attached). Is that normal, or
> did the previous owner possibly put it together with what was lying around?
>
> Thanks.
>
> Phillip
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