# Need center to center measurement for Tool 2079

Tony Hoffman auditony at gmail.com
Fri Mar 28 12:27:51 PDT 2008

```This is very interesting. And, I still use the impact for mine ;-)

On a side not, I worked at a shop when I was younger that had about a
3foot long 3/4" torque wrench that went to something like 800 lb-ft.
That was pretty handy. I think there was a BMW se did that was
something like 550 or 600 lb-ft. I know it was pretty tough to get
off, that's for sure. Oh, as if that wasn't enough torque to ensure it
not coming off, they use the permenant (red) loctite on it as well!

Tony

On Fri, Mar 28, 2008 at 3:09 PM, syljay <syljay at optonline.net> wrote:
>
> > From: "Kunz, Bob" <bob.kunz at hp.com>
> > The 'torque' thread rises again...
> >
> > The math is actually simple and will answer all your questions about length of extensions. It goes this way:
> >
> > T = Torque needed at the bolt
> > A = Applied torque of the wrench
> > L = length of the torque wrench
> > E = length of the extension
> >
> > A = (T * L) / (L + E)
> >
> > --bob
>
> ***** Yeah, aint this great!!!?  hehehe
>
> Did you know, that the tool 2079 torque value of 232 ft lbs only works
> if you use a torque wrench that is exactly 41" long? Thats something
> the Bentley forgot to tell you about.
>
> Here are the values of torque settings to get 332 ft-lbs at the bolt
> when using tool 2079 with various length torque wrenches:
>
> Length of wrench     torque setting
> 24"                  232 ft-lbs
> 30"                  238 ft-lbs
> 36"                  250 ft-lbs
> 41"                  258 ft-lbs <---------
> 48"                  266 ft-lbs
>
> Seems counter-intuitive, eh? One would think that the more
> macho(longer) the torque wrench, the lower the torque wrench setting
> to be used.
>
> To puzzle it out:
> 1. What force is exerted by the operator using a 41" wrench?
> force applied = torque/distance
> force applied = 258/3.416  = 75.5 lbs   (41"/12" = 3.416 ft)
>
> 2. What is the total lever arm that the crank bolt sees?
> Wrench length + tool 2079  = 41" + 11.75" = 52.75" = 4.4 ft
>
> 3. What is the torque on the bolt head?
> Torque = distance X force applied
>        = 4.4 ft X 75.5 lbs
>        = 332.2 ft lbs
>
>
> Are you still in disbelief?
> Think of it this way. If you had a 100 ft torque wrench, would the
> 11.75" tool 2079 length be significant? Nope! You can forget tool
> 2079. The longer the torque wrench becomes, the less significant is
> the extension length.
> What setting would you set the 100 ft torque wrench to get 332 ft-lbs
> at the crank bolt?
> 332 ft-lbs would be the setting.
>
>
> SJ in NJ
>
>
>
>
>
>
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