Need center to center measurement for Tool 2079

[syljay]

> From: George Selby <gselby4x4 at earthlink.net>

>>I'm making my own version of Tool 2079 - which will be 35" long. Then
>>I can use my Craftsman torque wrench with a 129 ft-lb setting to give
>>me 258 ft-lbs at the crank bolt.
>>
>>The archive info says that applied torque for the crankbolt is:
>>With tool 2079 = 258 ft-lbs
>>Without tool 2079 = 332 ft-lbs
>>
>>My calculation indicates the distance for tool 2079 should be 15.5
>>inches. A reference in the archives says 11 3/4 inches.
> 
> 
> A little confused here, is it going to be 35" long, or 15.5" long (or 11.75"?)
**** I was checking on the Bentley torque values. The numbers were not 
coming out right. And, that is because MY torque wrench is a different 
length than what Audi used when they designed tool 2079.
The Bentley numbers come out right if the torque wrench is 41" exactly.
I wrote another post today on this topic.


> 
> Furthermore, I think the net result is you need 332 ft-lbs at the 
> crank bolt, which means calculations attempting to give 258 ft-lbs at 
> the crank would be wrong.  Tool 2079 gives some extra leverage which 
> means 258 ft-lbs at the tool will result in 332 ft-lbs at the crank 
> bolt.  I can't remember enough physics to remember how to multiply 
> torque with an extension.
> 
> What I'm thinking that you're thinking right now is:  Tool 2079 
> assumes you can get a 258 ft-lb torque wrench.  You want to know how 
> much longer you need to make your 2079 tool (let's call it 2079a) so 
> that you can use your lower capacity torque wrench.
> 
> Doing some simple math here (proportions) gives me the following 
> rough guess at a solution to your problem:
> 
> If a 11.75" (assuming that's correct) extension gets you from 332 to 
> 258, that means each inch of length reduces the amount to torque at 
> the wrench by ~6.3 ft-lbs.  You need to drop the torque requirement 
> by 203 ft-lbs, which means you would need an extension ~32.25" long (203/6.3)
> 
> End result: a 35" tool 2079a would probably be a good length.
***** Bingo!
A 35" version of tool 2079 would only require a 110 ft-lbs setting for 
my Craftsman 17.5" length torque wrench. That is right in the middle 
of its range - perfect.

I will be using a steel pipe with a breaker bar slipped inside the 
pipe on one end and another breaker bar on the other end. Distance 
from drive center to drive center will be 35".
27 mm socket on one end for the crank bolt. The other end has 1/2" 
socket for the torque wrench to fit into.

Why use 35" a pipe? Cause that makes a perfect torque TRIPLER for my 
Craftsman 17.5" torque wrench. Makes it easy to figure out what 
setting to use for any desired final torque value on the bolt/nut.
332 ft-lbs at the bolt requires a 110 ft-lb setting on the torque 
wrench. We wont worry about them decimal places.

SJ in NJ