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Fabrication 101 Everyone has to start somewhere and for some, theOFN might be that somewhere.

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  #1  
Old 10-22-2013, 08:51 AM
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2Xtreme 2Xtreme is offline
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Do I NOT know how to use a torque wrench...?

I'm curious about a situation I ran into with my practically brand new, click style torque wrench (Kobalt) last night. I will try to describe the situation to the best of my ability, so please bear with me....

I needed to re-tourque a few bolts on the CJ, so I set the wrench to the desired setting and proceeded to click away.

BUT, although the wrench clicked, it would also continue to tighten the bolts after it clicked.
With each successive 'cycle' the wrench continued to tighten the bolts several less degrees beyond the click. Until eventually it only clicked without turning the bolt any further.

With that said, on one bolt it continued this process until I was sure the bolt was about to fail.

So my question is, is this the normal process for using this type of torque wrench? I was under the impression that once it clicked, it shouldn't allow you to continue tightening the bolt.

I understand this is not the highest quality TW. But I can't justify the cost of a Snap-On, or Matco. I am getting ready to attempt my first engine rebuild, and if this TW is no good, it will just be a waste of time and $$$.

Thanks in advance!

2X
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Old 10-22-2013, 09:49 AM
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when it clicks you're at the set torque.so stop then
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Old 10-22-2013, 10:10 AM
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Quote:
Originally Posted by dean View Post
when it clicks you're at the set torque.so stop then
In the two instances I spoke of, stopping at the initial click did not torque the intake enough to seal it, or the torque converter enough to keep it from knocking under load.

So does that mean my wrench is out of calibration?
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Old 10-22-2013, 11:01 AM
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Quote:
Originally Posted by dean View Post
when it clicks you're at the set torque.so stop then
Right. The click is just a signal to let you know to stop. There may be a little lost motion after the click, but most wrenches will allow you to continue tightening after the click.

Here's what Snap-On says on the subject:

http://www1.snapon.com/display/231/T...ueWrench08.pdf

I just bought a 3/8" torque wrench, and I looked on Garage Journal to see what people said about different brands. There's a ton of discussion over there. If I remember right, the Kobalt wrenches got good reviews from guys that own them.
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Old 10-22-2013, 11:03 AM
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Quote:
Originally Posted by 2Xtreme View Post
In the two instances I spoke of, stopping at the initial click did not torque the intake enough to seal it, or the torque converter enough to keep it from knocking under load.

So does that mean my wrench is out of calibration?
Maybe the threads needed cleaned? You are above 20% of the max rating of the torque wrench, right? They're pretty inaccurate when you try to use them below that value.
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  #6  
Old 10-22-2013, 11:20 AM
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Originally Posted by Graham08 View Post
Maybe the threads needed cleaned? You are above 20% of the max rating of the torque wrench, right? They're pretty inaccurate when you try to use them below that value.
Pretty sure.

I saw the reviews on garage Journal, that is why I was comfortable buying this one.

So now my question is, is this wrench good enough for a stock engine rebuild?
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Old 10-22-2013, 12:18 PM
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I would want to have it tested. If you continued to use it after reaching the set torque it could have damaged the internals.

The electronic clip on the end of a regular ratchet/breaker bar torque device that Harbor freight sells actually seems to get a good accuracy rating. It uses a strain gauge rather than a spring to detect torque at the head.

It is worth buying and checking calibration on the wrenches you have.

Here is what I am talking about.

http://www.harborfreight.com/digital...ter-68283.html


Carl
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Old 10-22-2013, 01:29 PM
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are you following the correct torque pattern?if you just start anywhere you could warp the intake or converter.
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Old 10-22-2013, 02:23 PM
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Quote:
Originally Posted by cbrogers View Post
I would want to have it tested. If you continued to use it after reaching the set torque it could have damaged the internals.

The electronic clip on the end of a regular ratchet/breaker bar torque device that Harbor freight sells actually seems to get a good accuracy rating. It uses a strain gauge rather than a spring to detect torque at the head.

It is worth buying and checking calibration on the wrenches you have.

Here is what I am talking about.

http://www.harborfreight.com/digital...ter-68283.html


Carl
Carl-

That unit goes between the ratchet handle and socket?
I've never seen one.
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Old 10-22-2013, 02:24 PM
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Quote:
Originally Posted by dean View Post
are you following the correct torque pattern?if you just start anywhere you could warp the intake or converter.
Absolutely!

Although there are only 3 bolts on the converter, so it's kind of tough to screw that one up... lol
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Old 10-22-2013, 03:53 PM
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"So how tight does it go?"
"Stop before you snap it off."
"Ok."


SNAP!

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Old 10-22-2013, 04:19 PM
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Quote:
Originally Posted by 2Xtreme View Post
Carl-

That unit goes between the ratchet handle and socket?
I've never seen one.
Yes, Pretty easy to use. Since it is measuring with a strain gauge the actual twist rate it is pretty accurate.

There was an article in JP I believe where they were comparing the accuracy of different torque wrenches and the were using a calibration facility to check after many uses, different ways of leaving the wrench set, and different types. Turns out that this little piece of equipment was accurate, repeatable and could be counted on. Actually it was so accurate that I would not hesitate using it to check calibration on my click type wrenches.

It is always best to have the certified, but for the price it is a good way to check a wrench that has been dropped or abused.


Be aware that there is a limit on that device of like 145 ft/lbs but you should be able to chuck it up in a vise and then run your click type till it clicks at say 100 ft/lbs and see what it is really doing.



Carl
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  #13  
Old 10-23-2013, 07:29 AM
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Great.
Thanks for the info.

I will grab one and check my wrench before starting my rebuild.

Thanks again!

2X
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  #14  
Old 10-23-2013, 05:07 PM
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Just remember

Tight is tight-
Too Tight is a new one!


Steve
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  #15  
Old 10-23-2013, 08:28 PM
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A few tips...

Don't use torque clicker torque wrenches at or anywhere near their lower setting. If a 1/2" torque wrench says 25-250ft-lb, just forget about using it below 35ft-lb because the accuracy of where it clicks and the strength of the click is weak - you may not even realize it has clicked.

When torquing, make sure you are moving in a smooth, continuous, steady speed rotation up until it clicks. Herky jerky movements will yield an inaccurate torque. A common mistake is to slow down as you approach the target torque - that is a good way to get less torque than you're supposed to.

Make sure you always leave your torque wrench in a relaxed state during storage, i.e. set to the lowest torque value setpoint. This will help maintain accuracy.

I always test my torque wrench for accuracy prior to use by putting the socket-square-drive in a vise and pulling the handle at a known distance from center using a spring gauge. Calculate force x distance to get the torque measured by the spring gauge and make sure it's close to your target. This method isn't perfect but it's better than not checking at all.

I recently picked up a digital wrench from Eastwood and it is a real interesting thing to operate. I love it, don't get me wrong, but the thing doesn't have that "give" when you hit the set point like a clicker wrench does, so it's very easy to go a little beyond. I think you're a little more likely to undertighten with a clicker wrench and more likely to overtighten with a digital wrench.

Also all this doesn't mean a damn thing if you have the wrong torque spec for the fastener. Make sure you get a torque spec from more than one source - misprints happen and it sucks to break bolts/studs or strip threads for something so stupid. I recently stripped an exhaust manifold thread on my aluminum LS heads because I was using too high a torque setting from aftermarket instructions - the OEM spec was about 50% of what was specified. Kicking myself for not double checking or realizing the torque was way too high for the fastener size.
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Last edited by TheBandit; 10-23-2013 at 08:32 PM.
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  #16  
Old 10-24-2013, 07:20 AM
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Quote:
Originally Posted by TheBandit View Post
...Also all this doesn't mean a damn thing if you have the wrong torque spec for the fastener. Make sure you get a torque spec from more than one source - misprints happen and it sucks to break bolts/studs or strip threads for something so stupid. I recently stripped an exhaust manifold thread on my aluminum LS heads because I was using too high a torque setting from aftermarket instructions - the OEM spec was about 50% of what was specified. Kicking myself for not double checking or realizing the torque was way too high for the fastener size.
^^^ THIS!

No one to blame but myself, as I read the chart wrong.
But I ended up trying to tighten a torque converter bolt to somewhere around 100+ ft/ pound, when it should have been 40.
Snapped that sucker off like I was Hercules....
Then snapped an extractor trying to get it out.
Net result = new torque converter....
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Old 10-24-2013, 08:05 AM
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Quote:
Originally Posted by TheBandit View Post
A few tips...

Don't use torque clicker torque wrenches at or anywhere near their lower setting. If a 1/2" torque wrench says 25-250ft-lb, just forget about using it below 35ft-lb because the accuracy of where it clicks and the strength of the click is weak - you may not even realize it has clicked.
Right on. Actually, most torque wrench manufacturers don't recommend using clickers below 20% of the full scale. So 50-250 ft-lb, 20-100, etc. I'm pretty sure it's because there is not enough preload on the spring in the mechanism to reliably click at the right torque when you're below 20% of the full scale.

The wrong torque spec thing reminds me of something dumb I did recently. I was reassembling the rear end for my sprint car, and was torquing ring gear bolts. Turns out there are two different style bolts, one needs 50 ft-lb, the other only 35. Apparently 50 ft-lb breaks the style with the lower torque spec. Fortunately they were through bolts with nuts. It forced me to replace them, which was a good thing anyway because they were of unknown age.
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  #18  
Old 10-24-2013, 09:30 PM
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Car craft did a review on Torq wrenches a little while back, here it is http://www.carcraft.com/techarticles...rench_testing/.

Helpful hints
Anytime you add an extension, you lose a small amount of torque(same goes for impacts).
Don't mistake in-lbs for ft-lbs, this was one of the first mistakes I made.
As said before, make sure bolt and hole threads are clean, also remove any liquid from the holes as this can cause incorrect readings or cracking.
In applications where accuracy is key, thread lube helps consistency.
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Old 10-24-2013, 11:00 PM
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Originally Posted by PDANKracing View Post
In applications where accuracy is key, thread lube helps consistency.
Be certain to adjust the torque spec when shifting from dry to wet or even lube to lube.

E
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  #20  
Old 10-25-2013, 07:35 AM
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Quote:
Originally Posted by PDANKracing View Post
Car craft did a review on Torq wrenches a little while back, here it is http://www.carcraft.com/techarticles...rench_testing/.

Helpful hints
Anytime you add an extension, you lose a small amount of torque(same goes for impacts).
Don't mistake in-lbs for ft-lbs, this was one of the first mistakes I made.
As said before, make sure bolt and hole threads are clean, also remove any liquid from the holes as this can cause incorrect readings or cracking.
In applications where accuracy is key, thread lube helps consistency.
Thanks for the link.
I'll definitely give that a read.

Thinking I need to chase the threads. Bolts in question have several rounds of anti-seize and torquing on them. Well, the holes do. Bolts are new.

What's the best way to clean out a blind hole? Thread chaser and air, I would imagine. Right?
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