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Discussion Starter #1
Is there some formula out there to use when when using adapters ? I have a torque value for a 1/4 drive but i only have a 3/8 torque wrench.
 

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I don't understand what you mean by torque value for a 1/4 drive. The size of the wrench has nothing to do with the value of the torque other than the larger the size, the more torque that can be applied. 20 lb-ft for a 1/4" drive is the same as 20 lb-ft for a 3/8" drive.
 

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I think you only need conversions if you are applying torque outside the axis where the torque is applied.

For instance, a socket is on the torque axis...a crows foot is not and would need some conversion.
 

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Are you asking for a in. lb. to ft. lb. conversion?
Or a nm. to ft. lb. conversion?
 

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Discussion Starter #6
Sorry for the cunfusion. The special tool i am using is 1/4 drive and i do not have a 1/4 torque wrench and i thought there was a some kind of conversion chart when you are using adapters .
 

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It's like Pfred said. If the tool is like a standard socket in that the axis of the tool is in line with the 1/4 to 3/8 adapter then no conversion is necessary. If the center of the axis is offset from the center axis of the torque wrench then you have to adjust the reading by the amount of the offset.

A picture of the tool would help us answer the question easily
 

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http://www.tpub.com/content/engine/14076/css/14076_47.htm

This has the mathmatical formula if you are using a torque adapter such as a crow foot. After doing the math you'll find there is no change in the torque setting if the adapter is at the 3 or 9 o'clock position.
If you are just using an adapter for a socket to go from 3/8 down to 1/4 inch, no torque adaptation is required.
 

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Your going to need a correction factor. From robw's article in his post you'll see:

Ta = Tw x (L + A)/L where:


To determine the actual torque applied to the part or fastener, assume that the length of the torque wrench is L and the length of the adapter is A. Assume also that Tw is the torque indicated on the scale of the torque wrench and Ta is the torque exerted at the end of the adapter. To determine Ta, simply multiply the torque indicated on the torque wrench (Tw) by the ratio of the total effective length of the assembly (L + A) to the length of the torque wrench (L)


The trick is knowing the actual (L) and (A) values. The (A) value in your case would be the distance from the center of the square hole of the socket to the centerline though the two pins. This could be determined pretty easily. The only thing I'm not sure of is how to measure the effective length of the wrench itself. I'm assuming it would be from the center of the square socket pin to the mid point on the handle where you hold, but that's only a guess. There is a metrology specialist on another board that could answer the question, but maybe somebody here has the answer also.
 

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Discussion Starter #13
Originally Posted by devon383
here is the tool i am using.

What is that used for? :shrug:
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it is for adjusting the tension on timing belts on jeep/dodge/chrysler/mistibushi engines. it is supposed to be 39 inch lbs. it is very crucial that i get it right or the valves and the pistons will be playing kissy face.
 

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O.K.
There is no difference in torque mesurements between 1/4" drive torque wrenches and 3/8" drive torque wrenches.
What is the book calling for?
Also, I always adjust ALL timing belts so that I can just barely twist the belt (at its longest run) 90 degrees from normal. I've more than likely done over a thousand timing belts.
 

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Just tighten it up 'til it strips the threads, then back it off 1/2 a turn. SHould be just about right...:joke:

Dave
Chrome... my favorite color!
 
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Originally Posted by devon383
here is the tool i am using.

What is that used for? :shrug:
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it is for adjusting the tension on timing belts on jeep/dodge/chrysler/mistibushi engines. it is supposed to be 39 inch lbs. it is very crucial that i get it right or the valves and the pistons will be playing kissy face.
You must of missed the thread about using this tool to torque your Crush Washer. :shrug:
 
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