torque wrench calibration

I bought a 3/8's great neck torgue wrench at autozone for $19.99. It
has a range from 120 to 960 Inch-pounds, and is also calibrated in
Meter-kilograms. It is a very gentle click torque wrench.

I had never used a torque wrench before, and thought surely it was
not accurate. I barely pulled on it and it clicked at 120 inch pounds.

So, I put the socket head in a vise, like someone on here suggested,
only with the handle parallel to the floor, and on it's side, the
socket head facing horizonatally. I then tied weights around a thin
rope and hung it over the handle, at precisly 9 inches from the Socket
head. I multiplied the inches of the leverage by the number of pounds
to get the inch-pounds.

Surprisely, despite all the dire warnings agains unscrewing the grip,
not oiling it, etc, etc, (that I had already violated before reading
all the way through the instruction booklet.), it was remarkable
accurate. I didn't realize I was that strong, I never realized what 30
foot pounds of torgue felt like, boy, I had been screwing those nuts
and bolts on WAYYY too tight.

I figure 20 bucks for the torque wrench will pay off in better
mileage after adjusting the axle spindle bolts to the suggested torque.

The torque wrench is probably +/- 10% accuracy, but I can deal with
it being off 3 foot pounds on a 30 lb torque nut, i can't deal with the
$130 dollars for the +/- 2% accurancy.

I wish you could re-calibrate it yourself, though, somehow.

Also, when calibrating, it is not necessary to change the weights so
much, just load up a 50 lbs and move it from 9 inches, to 8 inches, to
7 inches, etc, to increase/decrease the Inch-pounds. by moving the
rope fractions of inches til it clicked, i was able to find the +/-
accuracy fairly scientificly. If you could recalibrate the thing
yourself, you'd be crazy not to own one for $20 dollars.

It's kind of interesting how they calibrated it, it clicks at about
135 in-pounds at the 120 Inch pound setting(+5%), while it clicks at
about 460 inch pounds at the 480 inch pound setting (-5%).

That seems like an intelligent way to do it, a little too tight on
the light torqued nuts, a little too light on the heavily torqued nuts.

> wrote in message
ups.com...
> It's kind of interesting how they calibrated it, it clicks at about
> 135 in-pounds at the 120 Inch pound setting(+5%), while it clicks at
> about 460 inch pounds at the 480 inch pound setting (-5%).
>
> That seems like an intelligent way to do it, a little too tight on
> the light torqued nuts, a little too light on the heavily torqued nuts.
>

That isn't deliberate, it is because a spring is non-linear in force
throughout
it's travel range.

My only problem with click-torque wrenches is that sometimes you get a
fastner that reaches the required torque, then if you stop pulling on it,
after the fastner settles a few seconds, bit, it's torque goes down. This
is very obvious with a beam-type torque wrench.

Ted

Good post. Not enough of us use a torque wrench. In the old days of
all cast iron it was always "good and tight and a bit more". Now, with
all the aluminum, it is "too loose, torqued to spec, stripped".



On 17 Dec 2004 00:48:26 -0800, wrote:

>I bought a 3/8's great neck torgue wrench at autozone for $19.99. It
>has a range from 120 to 960 Inch-pounds, and is also calibrated in
>Meter-kilograms. It is a very gentle click torque wrench.
>
>I had never used a torque wrench before, and thought surely it was
>not accurate. I barely pulled on it and it clicked at 120 inch pounds.
>
>So, I put the socket head in a vise, like someone on here suggested,
>only with the handle parallel to the floor, and on it's side, the
>socket head facing horizonatally. I then tied weights around a thin
>rope and hung it over the handle, at precisly 9 inches from the Socket
>head. I multiplied the inches of the leverage by the number of pounds
>to get the inch-pounds.
>
>Surprisely, despite all the dire warnings agains unscrewing the grip,
>not oiling it, etc, etc, (that I had already violated before reading
>all the way through the instruction booklet.), it was remarkable
>accurate. I didn't realize I was that strong, I never realized what 30
>foot pounds of torgue felt like, boy, I had been screwing those nuts
>and bolts on WAYYY too tight.
>
>I figure 20 bucks for the torque wrench will pay off in better
>mileage after adjusting the axle spindle bolts to the suggested torque.
>
>The torque wrench is probably +/- 10% accuracy, but I can deal with
>it being off 3 foot pounds on a 30 lb torque nut, i can't deal with the
>$130 dollars for the +/- 2% accurancy.
>
>I wish you could re-calibrate it yourself, though, somehow.
>
>Also, when calibrating, it is not necessary to change the weights so
>much, just load up a 50 lbs and move it from 9 inches, to 8 inches, to
>7 inches, etc, to increase/decrease the Inch-pounds. by moving the
>rope fractions of inches til it clicked, i was able to find the +/-
>accuracy fairly scientificly. If you could recalibrate the thing
>yourself, you'd be crazy not to own one for $20 dollars.





"When a legislature undertakes to proscribe the exercise of a citizen's
constitutional rights it acts lawlessly and the citizen can take matters into
his own hands and proceed on the basis that such a law is no law at all."
- Justice William O. Douglas

MisterSkippy wrote:
> Good post. Not enough of us use a torque wrench. In the old days of
> all cast iron it was always "good and tight and a bit more". Now, with
> all the aluminum, it is "too loose, torqued to spec, stripped".
>
>

And a reminder... especially if you have aluminum wheels... recheck the
torque on those lugnuts a day or two after rotating or any time you've
had the wheels off.

Last week was the second time in 5 years my truck has decided to try
shedding the wheels. My truck has two modes for removing lugnuts - you
need to be the Hulk to get them off or they just come off by
themselves... and yes, I use a torque wrench. I forgot to check them a
second time a couple of days later and one wheel almost came off on me.
When I rechecked them a couple of lugs were only finger tight...

Ray

On Mon, 20 Dec 2004 02:15:41 GMT, Ray > wrote:

>MisterSkippy wrote:
>> Good post. Not enough of us use a torque wrench. In the old days of
>> all cast iron it was always "good and tight and a bit more". Now, with
>> all the aluminum, it is "too loose, torqued to spec, stripped".
>>
>>
>
>And a reminder... especially if you have aluminum wheels... recheck the
>torque on those lugnuts a day or two after rotating or any time you've
>had the wheels off.

I have aluminum alloy wheels also, and this is a notorious problem.

>Last week was the second time in 5 years my truck has decided to try
>shedding the wheels. My truck has two modes for removing lugnuts - you
>need to be the Hulk to get them off or they just come off by
>themselves... and yes, I use a torque wrench. I forgot to check them a
>second time a couple of days later and one wheel almost came off on me.
>When I rechecked them a couple of lugs were only finger tight...

That's the way they were when I bought the car from the dealership!

Every so often, I walk around the car with a torque wrench and make
sure they're at 80 pound/feet, which is what the dealer told me to set
them to. The tech at the dealership said they set =all= wheel nuts on
ford/Lincoln/mercury to 80 pound/feet, regardless of make/model.

I thought that was *curious,* but that's what I do now, since having
broken off a lug whilst torquing it to 100 pound/feet.

Lg


>Ray

Lawrence Glickman wrote:


>
> That's the way they were when I bought the car from the dealership!
>
> Every so often, I walk around the car with a torque wrench and make
> sure they're at 80 pound/feet, which is what the dealer told me to set
> them to. The tech at the dealership said they set =all= wheel nuts on
> ford/Lincoln/mercury to 80 pound/feet, regardless of make/model.
>
> I thought that was *curious,* but that's what I do now, since having
> broken off a lug whilst torquing it to 100 pound/feet.
>
> Lg
>
>
>
>>Ray
>
80 ft-lbs is a little low. The shop manual for my '92 Grand Marquis says
85-104 Lb-ft and the manual for my '96 Mark VIII says 85-105 Lb-ft.
I ususually set them around 95-100 lb-ft.
Stan K.

Lawrence Glickman wrote:
>
> Every so often, I walk around the car with a torque wrench and make
> sure they're at 80 pound/feet, which is what the dealer told me to set
> them to. The tech at the dealership said they set =all= wheel nuts on
> ford/Lincoln/mercury to 80 pound/feet, regardless of make/model.
>
> I thought that was *curious,* but that's what I do now, since having
> broken off a lug whilst torquing it to 100 pound/feet.
>
> Lg

My truck is a GM and it's 100. All three GM's I own with aluminum
wheels use 100. The wife's Beretta has never done that in 7 years...

Ray