Crank bolt torque for timing belt change (10v)

[SJ]

I've been puzzled by this also.
I'll break it down to the basics as I understand it. If I make an error
please correct me.
Extension = 1 ft
Torque wrench set at 258 ft lbs
What is the final torque on the bolt?

Since Torque = Force X lever
258 ft lbs = 258 lbs X 1 foot lever
Now we have a known force to play with. Me standing on a 1 foot 1"drive

Add a 1 foot extension to the 1 foot lever, the force is still 258 lbs. Me
standing on a 2 foot pipe slipped over the drive.

Torque = Force X lever
Torque = 258 lbs X 2 feet = 516 ft lbs

The Bentley says "258 ft lbs. Torque only applies when using long extension
2079"

A final torque of 516 lbs seems high to me.

This page has another explanation. http://www.norbar.com/faq.htm
There is also a torque calculator link there.

The formula at this site is:
M2  =  M1  x  L2/ L1

Where:
M2 is the torque on the bolt
M1 is the torque on the torque wrench
L1 is the torque wrench length
L2 is the total length of torque wrench and extension

Using this formula and my torque wrench measurement, I come up with 435 ft
lbs at the bolt for a 258 ft lb reading on the torque wrench.

SJ
85 Dodge PU, D-250, 318, auto
85 Audi 4k - - sold but still on the road
88 Audi 5kq
90 Audi 100q


> From: bob.rossato at att.net
> Subject: Re: Crank bolt torque for timing belt change (10v)
> To: "KUNZ,BOB (HP-Boise,ex1)" <bob.kunz at hp.com>
> >
> If you're using the 2079 extension (I get the impression you have one
since
> you knew the center-to-center length) then it doesn't matter what the
length
> of your torque wrench is.  Just apply 258 lb-ft of torque with the 2079 in
> line.  If you are looking to do it without the 2079, then the torque value
is
> 330 lb-ft, at least that's the approximate number I remember from my
Bentley.
>
> Bob
>
> > OK, guys. I've looked for the actual torque on this bolt and have found
so
> > far...
> > 330 ft-lbs at the bolt
> >
> > 450 ft-lbs at the bolt
> >
> > 400 ft-lbs at the bolt
> >
> > 258 ft-lbs at the end of the 2079 tool
> > The center to center length of the 2079 is 12 inches. If the length of
the
> > torque wrench is "L" and the torque setting on the wrench is "T" then
the
> > torque delivered to the end of the 2079 tool is: T * ((12+L)/L). This
> > assumes the 2079 and torque wrench are in line, otherwise we have to
apply a
> > sin function. So I'm missing one more variable, either the actual torque
I
> > need or the length of the torque wrench that Bentley describes. Picture
> > 17-223 in the Bentley shows that clearly the torque wrench is longer
than
> > the 2079 but then the bar goes outside the picture frame.
> > So, anybody have the actual torque for this bolt?
> > --bob