Now we know who has (and who has not) ever removed a Honda crankshaft pulley bolt!
Does it Damage Click Stop Torque Wrenches to Loosen Nuts
- Thread starter TimeFlies
- Start date
Now we know who has (and who has not) ever removed a Honda crankshaft pulley bolt!
Yeah, those are torqued to about 180 ft lbs but seem to require 1800 ft lbs to remove!Now we know who has (and who has not) ever removed a Honda crankshaft pulley bolt!
Ok, don't be exaggerating. You know good and well it only takes 1637 ft lbs to remove.
Take off some Euro lug bolts after even a few months that were torqued to 100lb, I literally broke a Proto 17mm impact socket using a 6ft breaker bar/pipe combo. It took a 1200 lb impact with a weighted socket to break it free.
Sure if the bolt is a L/hand thread and it is loose there is no problem tightening it with a TW in reverse if its available on the tool.
Sure if the bolt is a L/hand thread and it is loose there is no problem tightening it with a TW in reverse if its available on the tool.
I saw someone do it once on an old Dodge PU stuck lug nut. It damaged a 250#ft 1/2" drive torque wrench. The guy used it because it was long...
Why would anyone do such a thing?
Why would anyone do such a thing?
No I didn't.
Every new one I've bought goes left and right.
Some old vehicles even have left hand wheel nuts to tighten.
Heard all my life not to loosen stuff with a torque wrench.
A while back I had no choice, so i used my expensive snap on to loosen a bunch of nuts. In my head it was now junk, but I got home to my shop and checked it against my other torque wrenches, and it seems fine.
So I sent it to be calibrated, and the sheet enclosed when it came back was that it was fine. At the bottom it was a bit off, in the middle basically dead on, at the top a bit off, but no different than the last time I sent it to be calibrated.
So as an experiment, i ordered two elcheapo torque wrenches on Amazon. In 3/8 & 1/2 inch drive, checked them against my other torque wrenches, and was impressed by their accuracy for cheap tools. Then i beat on them, dropped them, and loosened anything that I could find to loosen with them.
Checked them again and while slightly less accurate, not much less.
I'm not saying use yours for loosening bolts, but also don't panic to bad if you have to, it may not have done anything to it.
JHZR2
Staff member
Someplace I read that you shouldn’t even use a ratchet for the initial breaking torque…
Some old Mopars use left hand thread lug nuts on IIRC the right side. He may have been tightening it not loosening,
Yep. They have an "L" stamped on the end of the stud. This was an old beat up tree trimmer truck. And I do mean beat. But it could haul a load!
You probably remember service stations used to put the gun on rock-and-roll at go to town installing wheels. Of course I never did that...
Many decades ago, when I worked at a company that built a major Space Shuttle component, torque was very critical. Anyone that used a torque wrench actually had to go to a class, to be certified.
Training included being told that a click type torque wrench, once used to torque in one direction or the other, was to always be used only in that direction. The torque wrenches I used were actually boldly labeled "Use in Clockwise Direction Only". They were also, only calibrated in that direction that they were used for.
If you want to torque wrench that can be used in either CW or CCW, get a beam type torque wrench.
Training included being told that a click type torque wrench, once used to torque in one direction or the other, was to always be used only in that direction. The torque wrenches I used were actually boldly labeled "Use in Clockwise Direction Only". They were also, only calibrated in that direction that they were used for.
If you want to torque wrench that can be used in either CW or CCW, get a beam type torque wrench.
I remember the old Chrysler CCW wheel studs, but I had forgotten about the "L" stamp on the end of the stud. Thanks for the walk down memory lane.
I have a 3/4 inch breaker bar and 3/4 inch socket for my 17 inch rims on my 3/4 ton. Ho-ho-ho.
I could probably start a new topic for this, but do you reduce the torque when using anti-seize and by how much?
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Not with my Husky or Craftsman as it can damage them. Even says so in the owners manual.
Noooo. Mods, stop it before it spreads!
The only place I would use a torque wrench to undo bolts, is wheel nuts/bolts. I know they won't have any of that on my cars.
I do use breaker bars, and pipe extensions, but I disagree with the statement that undoing any nut/bolt breaks a torque wrench. But I guess common sense is very uncommon.
dnewton3
Staff member
I have several of these "clicker" torque wrenches.
Short answer: using a tool does not damage it; abusing a tool does.
Long answer below: ...
I do agree it's not a good practice to use it as a breaker bar. But it's not damaging to the tool as long as the torque to break the bolt loose does not exceed the normal operating range of the torque wrench.
If you've ever taken one apart, these are merely spring-loaded detent devices. When you turn the handle barrel, it uses the threaded mechanism inside to compress the spring (essentially a "preload" effect). The spring uses a mandrel/plunger to push up against a ball-detent. In use, as the desired torque setting is crested, the spring loaded plunger pops past the detent (that's the "click"). It's literally that simple of a device. The linear rate of travel in the threaded handle combined with the linear rate of the spring gives a predictable result of force against the ball detent. If the spring is well made and of good quality material, the "spring rate" will not change over the life of the tool by any substantial manner. The only way these can "adjusted" (calibrated) is that shims can be added or subtracted under the spring to help "zero" (for a lack of a better term) the device, so that a target value on the handle setting is truly achieved when the detent activates. Generally, once they are set at the factory, they're good for the life of the tool.
Breaking torque loose to remove a traditional bolt/nut (LH counterclockwise) is simply popping the detent over in the opposite direction of "normal" (RH clockwise) use. As already mentioned, any LH bolt would actually use this function; it's not "wrong" to use the tool in this manner. Of the ones I've taken apart, the detent ramp is identical in both directions; thereby allowing multi-directional use.
There are two ways you could use the tool as a "breaker bar".
- leave the setting at zero; there will be no pressure whatsoever on the spring and detent. The only concern would be if you exceed the design capability of the tool itself; that of the pivot pin in the head, or the bending moment of the shaft, etc. For goodness sake, don't use a 1/4" clicker-wrench to break loose some lugnuts on your SuperDuty!!!
- set the torque value ABOVE the expected break-loose value, but always below the max allowable setting. In this manner, the detent would never be activated. If, for example, you wanted to break loose a fastener with approximately 80 ft-lbs expected torque, and your wrench is capable of 150 ft-lb, there's no conceivable manner that you would damage the wrench if you set it to 120 fl-lb for that 80 ft-lb task.
Every time you "pop" over the detent, there is some really small amount of wear going on. For the average user at home, you'll never wear the tool out. If it were used in a production operation, literally hundreds of "pops" per shift, for months on end, then you might alter the detent enough that it needed to be changed out. There are actually repair parts available for worn out detent wrenches. But as I said, it takes MANY THOUSANDS of "pops" to wear them out; it's a function of tool quality and quantity of uses. Most folks at home will never wear out a detent.
I personally have used my t-wrenches for decades, and when I took them to my QC lab and checked them on our ISO certified torque cell, they were still perfectly serviceable and in spec, after years and years of use. But I used them hundreds of times; not thousands of times.
I cannot stress this enough; never exceed the operating range of the tool no matter what you're doing with it !!! The reason we see manufacturer statements about not using them as breaker bars is because people are idiots; they tend to exceed the design criteria of the tool. THAT is what damages a torque-wrench. We also have to acknowledge that most torque wrenches today are a combination of the torque function AND a ratcheting head. What limits the capacity of the tool is more likely the ratchet system and NOT the detent. You're gonna break the ratchet (gear or pawl) far sooner than the detent if you "over torque" the tool.
Again, I agree it's not the proper tool for a breaker-bar job, but a true understanding of the working principle allows us to make an educated response here. It's not ideal, but it's also not going to damage anything to any degree worth worrying about as long as the unit isn't stressed past it's design limits.
Short answer: using a tool does not damage it; abusing a tool does.
Long answer below: ...
I do agree it's not a good practice to use it as a breaker bar. But it's not damaging to the tool as long as the torque to break the bolt loose does not exceed the normal operating range of the torque wrench.
If you've ever taken one apart, these are merely spring-loaded detent devices. When you turn the handle barrel, it uses the threaded mechanism inside to compress the spring (essentially a "preload" effect). The spring uses a mandrel/plunger to push up against a ball-detent. In use, as the desired torque setting is crested, the spring loaded plunger pops past the detent (that's the "click"). It's literally that simple of a device. The linear rate of travel in the threaded handle combined with the linear rate of the spring gives a predictable result of force against the ball detent. If the spring is well made and of good quality material, the "spring rate" will not change over the life of the tool by any substantial manner. The only way these can "adjusted" (calibrated) is that shims can be added or subtracted under the spring to help "zero" (for a lack of a better term) the device, so that a target value on the handle setting is truly achieved when the detent activates. Generally, once they are set at the factory, they're good for the life of the tool.
Breaking torque loose to remove a traditional bolt/nut (LH counterclockwise) is simply popping the detent over in the opposite direction of "normal" (RH clockwise) use. As already mentioned, any LH bolt would actually use this function; it's not "wrong" to use the tool in this manner. Of the ones I've taken apart, the detent ramp is identical in both directions; thereby allowing multi-directional use.
There are two ways you could use the tool as a "breaker bar".
- leave the setting at zero; there will be no pressure whatsoever on the spring and detent. The only concern would be if you exceed the design capability of the tool itself; that of the pivot pin in the head, or the bending moment of the shaft, etc. For goodness sake, don't use a 1/4" clicker-wrench to break loose some lugnuts on your SuperDuty!!!
- set the torque value ABOVE the expected break-loose value, but always below the max allowable setting. In this manner, the detent would never be activated. If, for example, you wanted to break loose a fastener with approximately 80 ft-lbs expected torque, and your wrench is capable of 150 ft-lb, there's no conceivable manner that you would damage the wrench if you set it to 120 fl-lb for that 80 ft-lb task.
Every time you "pop" over the detent, there is some really small amount of wear going on. For the average user at home, you'll never wear the tool out. If it were used in a production operation, literally hundreds of "pops" per shift, for months on end, then you might alter the detent enough that it needed to be changed out. There are actually repair parts available for worn out detent wrenches. But as I said, it takes MANY THOUSANDS of "pops" to wear them out; it's a function of tool quality and quantity of uses. Most folks at home will never wear out a detent.
I personally have used my t-wrenches for decades, and when I took them to my QC lab and checked them on our ISO certified torque cell, they were still perfectly serviceable and in spec, after years and years of use. But I used them hundreds of times; not thousands of times.
I cannot stress this enough; never exceed the operating range of the tool no matter what you're doing with it !!! The reason we see manufacturer statements about not using them as breaker bars is because people are idiots; they tend to exceed the design criteria of the tool. THAT is what damages a torque-wrench. We also have to acknowledge that most torque wrenches today are a combination of the torque function AND a ratcheting head. What limits the capacity of the tool is more likely the ratchet system and NOT the detent. You're gonna break the ratchet (gear or pawl) far sooner than the detent if you "over torque" the tool.
Again, I agree it's not the proper tool for a breaker-bar job, but a true understanding of the working principle allows us to make an educated response here. It's not ideal, but it's also not going to damage anything to any degree worth worrying about as long as the unit isn't stressed past it's design limits.
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I've always been told 10% but there's soooo many variables I think in truth it's difficult to say.
TTC might have played around with that. They have a good episode on TWs where they drop them, dispel the the "double click" myth, and try to see if anything really changes with how aggressively you approach the target. The synopsis is that most of it's more idiot-proof than you might think (thankfully!!). They did see if thread lock affects torque IIRC
I'll say this: on lugnuts I've gotten in the habit of starting over after I complete my star pattern. I'd say 90% of the time #1 and #2 move again a little bit, but not #3+. I always torque with the vehicle partially supported on the lift arms and weighted just enough to keep the tires from spinning. Still, I think the first two seat the WMS and you're not getting true torque until #3 and later. Does it really matter? Almost surely not or we'd see more problems in the field.
