Thanks for the detailed explanation. I see the slots now. Looks like
I'll be putting some threadlockers in mine to help keep the lower nut
in place, as it's not worth it for me to send it in for calibration.
$25 plus shipping both ways will cost the same as a new wrench with
the annual sale, and I don't need a laboratory-grade certification.

I wonder if the detents have something to do with the high rate of
complaints about the plastic lock ring breaking (the Kobalt uses a
metal ring without detents). I suppose if the lock ring isn't loosed
up fully before adjusting, the force of turning will be transferred to
the plastic ring. At least that's what I supposed will hold the
setting when "locked".

I was at Lowe's earlier, their Danaher-made torque wrenches say no
hassle lifetime in big letters under the brand name "Kobalt", but the
same 90day/1year in fine print as Sears. Oh well, until I get a $400
Snap On I guess. Thanks again!

Among the excellent articles, torque wrench calibration on motor.com:
http://www.motor.com/article_pdf_dow...article_ID=516





On Nov 23, 12:41*pm, Tegger <inva...@invalid.inv> wrote:
> johngd...@hotmail.com wrote in news:7d23d43d-aed8-42ad-824b-
> 3be97cd2a...@q30g2000prq.googlegroups.com:
>
> > Nice writeup on opening your old torque wrench.
>
> > Is it right that the upper nut in the handle was held in place by the
> > plastic molding of the handle? So there is less chance of it rotating
> > out of place than the lower nut?
>
> The upper and lower nuts together clamp together the handle and the
> threaded shaft. This is how the wrench maintains its calibration. The
> handle and the shaft MUST NOT ever come out of phase.
>
> The upper nut does indeed sit in a matching hexagonal recess in the handle.
> Unless the handle should pull down sufficiently to allow the hex recess to
> come fully away from the upper nut, the nut and handle will stay in phase..
> However...if the lower nut comes loose, the upper nut will be loose as
> well, and will rotate relative to the threaded shaft (coming out of phase),
> throwing calibration off, which is exactly what happened to me.
>
>
>
> > Also, didn't exactly see where the detent feels come from. I guess
> > from the plastic lock ring area?
>
> If you look closely at the bottom of the wrench's body, you will see a
> series of long, shallow slots milled into the body. These are oriented
> axially, and spaced radially, around the body. (If they were cut all the
> way through, they would make the bottom of the body resemble a military
> rifle's flash suppressor.) There is a small nib, or protrusion, on the
> inside top of the plastic handle that indexes into the slots. When you turn
> the handle, its top flexes sufficient to allow the protrusion to ride out
> of one slot and fall into the next, giving the handle that "click" feeling
> as you wind the setting up or down.
>
> There are ten slots, of course, one for each pound as you rotate from 1
> through 0 up each ten pounds of scale marking.
>
> I'm not sure how the locking ring functions; it never occurred to me to
> examine that assembly.
>
>
>
> > The Lowe's Kobalt torque wrenches are also made by Danaher, but do
> > carry a lifetime warranty.
>
> That's interesting. Sears' "lifetime" warranty essentially only covers
> tools without moving parts, so the torque wrench is not covered.
>
> --
> Tegger
>
> The Unofficial Honda/Acura FAQwww.tegger.com/hondafaq/