Re: AAAARGHH!!! THE DREADED TORQUE THREAD!!! RUN FOR THE HILLS!!!

[Luis Marques <marques@ti.com>]

>>> - Crankshaft bolt torque. I have the locking tool (2084) and the
>>> extension (2079), thanks for the generosity of Gurdev Sethi. I have
>>> read many times that the correct torque with the extension is 258
>>> ft-lbs. I take that to mean that you should set your torque wrench
>>> for 258 ft-lbs--but that doesn't make any sense to me. You have to
>>> consider the length of the torque wrench, right?
>>
>> AAAARGHH!!!  THE DREADED TORQUE THREAD!!! RUN FOR THE HILLS!!!
>>
> Heh, Heh, Heh, I loved that thread. It was violently argued for
> months. There were free body diagrams and torques and force times
> distances floating all over the pages. But unlike so many threads that
> are unresolvable (dare I mention "Torsen") this thread was Engineering
> Mechanics/Statics 101. And yes Wallace, set your torque wrench to 258
> ft. lbs. But please, please, don't ask why.

Oh, yea, I remember that one.  Without going into free-body diagrams and
all that, yes, 258 ft-lbs is the right torque - but ONLY with said
extension, ONLY with a certain length torque wrench, ONLY pulling on it
at a specific point, and ONLY when the torque wrench is in-line with the
extension.  Otherwise you screw-up the torque-multiplying factor and end
up under or over torqueing (sp?) the crankshaft bolt.

> Put weight of mechanic at distance along pipe from the center of
> the bolt (in feet) given by 332/weight of mechanic (lbs).
> Pipe must be horizontal.

This also works, and is what I do.  Or you can get a BIG torque wrench
and tighten to ~350 ft-lbs without the extension.  A h*ll of a lot
easier than trying to figure out the different lengths of torque
wrenches, extensions, and angles, IMHO.

Luis Marques
'87 4kcsq