John N.----Check the accuracy of the torque wrench by setting it at 45
lb. and fit a socket to one of the wheel lug nuts. It should click well
before the nut further tightens. You could also "practice" on a nut and
bolt in a bench vice.
Most of the time there's enough residual oil in the rod threads, so
leave the bolts clean and dry. Compare their length to one of the known
old bolts.
Take a look at your old rod bolts. If they're not stretched (spin a nut
down to the root thread) re-use them. Also question the place that sold
you the new bolts, if the torque wrench checks out OK.
Run a tap down the rod threads to cut out any metal pickup. They'll
probably be allright, as deformation or stretching generally occurs in
areas where the threads are not captive. (Unless a bolt bottoms out)
Dick
From: johncnorth@gmail.com(John North)
These are new bolts. I did oil the threads and the head. However
the old bolts torqued up just fine using this method... Not sure how
I'd clean the threads in the rods at this point...
John
On Mon, Mar 31, 2008 at 8:30 PM, Michael Porter <mdporter@dfn.com>
wrote:
John North wrote:
I have read that these bolts should be torqued in three
equal stages. Given the spec range of 38-46, I tried 20, 31 then 42. I
backed off
the nut between the three torques. I didn't have the guts to complete
the last one, because the bolt made at least two full turns after being
finger tight. When I removed the bolt, there is clear thinning in the
last 5 or so threads and the bolt has stretched .114.
I tried just torquing a bolt up to 40 and got about 1.5 full turns after
the bolt became finger tight before I ran out of courage again and
stopped. This one has stretched about .015, but did not torque up before
I gave up.
Does this sound right or should I suspect the bolts are not good? I am
real scared of shearing off a bolt in the rod...
Time for new bolts. If they've remained stretched after being
torqued, that means they've yielded.
The torques normally specified for a dry fit. If you lubricated
the hardware in any way, then they likely have been over-torqued. If
you fitted them dry, then there's the real possibility that they
stretched during previous running or a previous installation.
Cheers.
--
Michael Porter
Roswell, NM
Never let anyone drive you crazy when you know it's within walking
distance....
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