[alfa] Re: Suspension bolt torque disaster

["skippatnode" <skippatnode@xxxxxxx>]

Jon,

1 & 2.  I would clamp the pan in place with a good "C" Clamp before removing
those bolts.

3.  Sorry, can't help with that one.

4 & 5.  You need to have the calibration checked on that torque wrench.
Especially if it is a "Clicker" Type.  They go out of calibration with great
regularity and even more so if you store them with tension on the adjuster
spring.  In the aviation business, it is required to get torgue wrenches
calibrated on a regular basis (every few months) and I would not dare to guess
how many are rejected because they are beyond repair and won't adjust.
    If you want a fairly economical torque wrench for home use, get a
"Deflective Beam" type with the torque you most commonly use at it's
mid-scale. They are a PIA to use sometimes, but they seem to stay in cal a lot
better.  All torque wrenches are only accurate at mid range and vary a lot at
extreme ends of their range.
    If your torque wrench turns out to be OK, then probably somebody
overtorqued those fasteners before you got to them.  Dirty threads won't cause
them to strip, rather it will cause them to reach their torque before they are
actually as tight as they should be.
    Or, if your torque wrench turns out to be bad, then you have the problem
of what to do with that engine you just put together with it.  Ouch!!!
Skip Patnode
67 Duetto
Norfolk, Va


Date: Sat, 13 Sep 2003 20:59:00 -0700
From: Jon Pike <jhpike@domain.elided>
Subject: [alfa] Suspension bolt torque disaster

OK,  We've somehow done it again..

Marcia and I were putting the spring pan back up, on our Spider's
disassembled front suspension,  and after she replaced the threaded rods
with the original bolts,  I had the job of torquing things up.

Well,  the first one started tightening,  and thinking I was perhaps
flattening a slightly cupped washer I kept going..  and going...  Sure
enough,  the (#*%^ thing no longer gets tighter.  Not fully appriciating
that disaster has happened,  after all, the wrench was set to the right
torque, (61-66 ft/lb, I set to 62) and another bolt firmed up and held
nicely, earlier.. I tried a second bolt... the same thing happened!!

I now have the two outer (closer to the wheel) bolts of the spring pan
with compromised threads,  and no longer loosening.

Questions:

1.  Can I trust the other bolt to hold while I cut off the nut or bolt
head to get the other out?  I'm assuming that both outer bolts having
problems is a rather dangerous situation.

2.  What's the best way to get these out,  without risking a spring
accident?

3.  Since one is the special double ended bolt that is used to attach
the swaybar link block to the spring pan,  where can I find a
replacement part?

4. Why the hell did this happen? Could it be my cheap torque wrench is
way off?  I didn't clean the threads completley, can some dirt cause
failure?  Were the nuts or bolt threads possibly damaged and ready to
fail? Is there some thing we missed someplace about doing this job?

5.  Should one always use brand new fasteners in cases like this?

Thanks!

Jon and Marcia
77 Spider
Irvine CA
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