more crank bolt....

[SJ]

Ameer is asking the same questions that I was. The numbers dont add up. Even
the theory is puzzling. But I think I can remedy the theory issue with some
use of pencil and paper.

The issue is not the plus or minus of a few pounds of torque.
The issue is what is the actual number of foot pounds that the bolt should
be torqued to. There is a big difference between 340 ft lbs and 516 ft lbs .
. or the 435 ft lbs that the extension formula comes up with.

The only valid number that I can find is the 258 ft lbs in conjunction with
the 2079 tool. These numbers are stated in most Repair manuals.
Where did the 340 ft lbs come from?
Where did the 332 ft lbs on Phil Paynes web page come from? That's for a
UR-Q.
Why is all this "data" not adding up?

I for one am curious. Will the real number please stand up!??

Words mean things. For example:
The Haynes manual states "...coat the threads of the center bolt with a
liquid locking agent . . ". Most of us think the "locking agent" is
something like Locktite.
My parts guy used to be a wrench. To undo one of these bolts, he had to put
the car on a lift, use a BIG pipe on a BIG breaker bar, then lower the car
onto the BIG pipe in order to break the bolt tension and unscrew it. He had
to do this several times in succession before he succeded. Impact wrenches
had no "impact" on the problem.
Now I read from Phils post on this topic, that  "I would translate the
latter as: 'Apply a film of AMV 188 001 02 corrosion preventive to the
threads and mating surfaces of the bolt head.' "    So, the "locking agent"
turns out to be anti-seize compound? No wonder that we are breaking our
balls . . .I mean bars . .when trying to undo this bolt.

Another puzzle, Phils torque spec page says " All values given are for dry
threads". But dont we need to apply this corrosion preventative to the bolt?
Does that not act as a lubricant?

Can the bolt torque problem also be the end result of a translation error of
a few word, or word, or number? Or, maybe the number itself is in error?
Maybe "258" is an error? If you apply the extension formula using 158 ft
lbs, the answer is 316 ft lbs on the bolt. . . .thats pretty close to the
332 and 340 numbers mentioned.  And what is the actual tension on the bolt
if you throw in the "corrosion preventative" variable into the pot.
Maybe 158, plus 2079, plus corrosion preventative comes up to 340?  Sounds
very reasonable to me.
Interesting, hmmmmmm?

So, the real issue, at least for me,  is that 2 + 2 is not coming out to 4.

Those of us that are interested in the extension theory also might have a
secondary agenda. I might want to make an extension so I can use my
"underpowered" torque wrenches for other work. My ft lb torque wrench only
goes to 250 ft lbs. I help my friend with his tractor. Everything on the
tractor is BIG. I would like to make a torque "Doubler", even a "Tripler"
extension for my torque wrench. Also, I have two inch-pound torque wrenches.
One ends at 200 in lbs . . .the other one starts at 400 in lbs. I have a gap
in the middle. An "25% or 50% extension" would solve that problem.

A doubler seems simple . . if the torque wrench is 24 inches long . .make
the extension 24 inches also. Even the formula works for this. But the
extension formula does not seem to work when we discuss the data regarding
the crank bolt.

Maybe the 12" dimension stated for the 2079 tool is incorrect? That would
throw off all the calculated numbers. Can anyone verify that length?

SJ


> From: "Al Powell" <apowell at gocougs.wsu.edu>
> Subject: more crank bolt....
> To: <quattro at audifans.com>
> Ameer Antar <antar at comcast.net> said:
> >
> > I'm not sure why I bother, but shouldn't the torque actually be a lot
more
> than that? <snip>
> So then you are also adding another foot of
> extension, so the new torque should be something like 258 lbs * 2 ft = 516
> ft-lbs. <snip>
> I doubt you'd need to torque it that high to be safe, but it seems like
that's
> what Audi wanted you to do.
>
> > -Ameer

> I think Ameer is missing the point and confusing his math. And this is
> really scary to me, as I am never the first to grasp math, but.......
>
> In the first and mostest basic place, WHO CARES whether you're a few
pounds
> off??? <snip>

> You're thinking too much and making it too much work. Audi is terminally
anal, and
> we already know that....so we all learn to disregard their instructions at
> times that make sense to us.
>
> Second, the math is simple enough even for me....

> And as I said earlier, 340 pounds = close enough!!!!!!!!!!!
>
> Since the desired torque on the bolt is around 350 bs/ft,
> In the third place, I don't really care whether Audi wanted me to do, nor
> whether they would get their panties in a wad if I was off by 10 lbs/ft
when
> I tighten the bolt. As long as I get the bolt torqued close enough to stay
> put and do its job, the rest is immaterial.
>
> Al Powell