more crank bolt....

[Alan Pritchard]

Uurm..... I can't believe im wrong on this point, but whatever setting you
set on the torque wrench, is what you'll get (allowing for inaccuracies in
the wrench itself). Now this is true of the type of wrench where you dial in
a torque, and you get a click when you have achieved that torque.
If, however you use a wrench with the needle showing you what torque you are
applying, this can change depending on whether or not you use a an
extension/push in a different place. Im not too familiar with this type and
am just commenting on info provided by one of my office colleagues.
 Is this where the confusion is? 
 -----Original Message-----
From: 	Ameer Antar [mailto:antar at comcast.net] 
Sent:	02 December 2003 12:57
To:	quattro at audifans.com
Cc:	Al Powell
Subject:	Re: more crank bolt....

Yes, I agree when torque is that high close enough is close enough, but I
was worried that it was a much higher number. I was just bringing up a
concern, and I wasn't sure that I was doing the physics right (the math was
fine). The point that I got wrong was that it does matter how long the
t-wrench is. I assumed this b/c in the manual it makes no mention of the
length of the wrench. Now, I guess that's b/c there must be an unspoken
industry standard for torque wrench lengths for a given range. So now, I can
calculate and match the numbers in the original post. I have seen 2 250
ft-lb wrenches that are 30", so I will assume that's what Audi used. So, to
get 258 ft-lbs of torque at the wrench head, you need 258ft-lbs/2.5 ft =
103.2 lbs. Then add the 1 ft extension and you get 3.5ft * 103.2lbs = 361.2
ft-lbs. Now I feel much better that the numbers match.

So exactly where are you getting these numbers: 85 lbs and 4 ft? I haven't
seen these in any Audi manual. Now, what's w/ the attitude? I don't really
see that I've done such a bad thing. I wasn't worried over a few ft-lbs,
more like a hundred or more, and that would be enough of a difference to
cause problems. Also, there was another lister who I won't mention who had
the same exact thinking/concerns as me, but you decided to focus on my post.
Another lister noticed my mistake and was able to point this out in a much
more palatable way. Everyone makes mistakes and it's important to help each
other see them but there are more reasonable ways of doing this.

-Ameer

---Original Message---
Date: Mon, 1 Dec 2003 19:06:03 -0700
From: "Al Powell" <apowell at gocougs.wsu.edu>
Subject: more crank bolt....
To: <quattro at audifans.com>
Message-ID: <BPEGLFDNGGDDBECLDDPAKEONCCAA.apowell at gocougs.wsu.edu>
Content-Type: text/plain;	charset="us-ascii"

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??? As  explained in the first post, it simply doesn't matter because you
have considerable margin for error with no impact on the outcome. 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....

Torque = force x distance
Example:
T1 = F1 x L1 = 10 lbs x 2 ft = 20 ftlbs
T2 = F2 x L2 = 20 lbs x 1 ft = 20 ftlbs
Therefore, T1 = T2
Therefore, 85 pounds at 4 feet = 340 pounds at 1 foot.
And as I said earlier, 340 pounds = close enough!!!!!!!!!!!

Since the desired torque on the bolt is around 350 bs/ft, get the four foot
pipe, slide it over the breaker bar, apply a good grunt worth of effort to
tighten the bolt, and unless you're either relatively weak or a weightlifter
who bench presses extraordinary weight, you're going to be in the right
range. After that, just drop it - you're done.

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
apowell at gocougs.wsu.edu
1958 Fiat 1200 Transformabile Spyder
1983 Datsun 280ZX Turbo
1993 Audi 90Q
1997 Chebby Blazer
1999 Chebby Blazer
************************************



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