Snap-on Techwrench issue with tightening lug nuts

[metaphysician]

I splurged on a Snap-On Techwrench TECH2FR100 (3/8" drive, 5-100 ft/lbs) for general work around the garage and cars/motorcycles. I was changing my oil/rotating tires on the new car and ran into some issues. The wrench did not have a problem for the 30 ft/lb required on the oil pan drain plug, but when I went to tighten the lug nuts to 80 ft/lbs, the wrench kept resetting (---- on screen and shut off).

According to the manual:
"A rapidly pulsing tone indicates that the wrench full-scale capacity is exceeded and the user must stop increasing torque. At 125% of wrench capacity the display will show"----" to indicate that possible damage may have occurred to the wrench. Push ON /ZERO key to initiate self-test. If the wrench has been damaged, the display will read "Err0" indicating that repair is necessary."

I do not get the "Err0" and the wrench seems to reset fine. I understand what the tool is doing, but not sure why it's happening. I believe I am holding the wrench correctly (hand at the end of the handle and other hand holding wrench head onto lug nut so it doesn't fall out and scratch my wheels) and taking my time with slow torquing. I know that using a torque wrench too close to its upper and lower limits will effect its accuracy and long-term calibration, but I would've thought 80 ft/lbs would be fine for this wrench.

Any ideas? Am I missing something or is the 80 ft/lbs too close to its limit and it's protecting itself? I am using a 21mm 1/2" drive socket (actually an impact socket) with a 3/8 > 1/2" adapter. Is this related to my problem?

Thanks!

 

[abk241]

Out of calibration?
I honestly don't think the tool knows the difference between an impact socket and a standard one.
Talk to your SO driver.

 

[LordPsychon]

Sounds like a calibration issue to me too. 20 extra ft-lbs would only take it to 100% tolerance and 55 more ft-lbs would get you to that 125%.

 

[country83]

Probably battery end cap losing connection briefly. The early handles were prone to it if you put your hand on the end of the handle at the end cap. Technically, you're supposed to put your hand on the handle where the black rubber molding is, not the end cap. If you pull too hard on an early end cap it'll lose connection and reset the wrench.

 

[Jon.R]

I had that problem with my 1/2 and it was the end cap not being tight enough!

 

[metaphysician]

Now that you mention it, I was having problems with the end cap. It was either too tight or too loose and the wrench would have problems turning and staying on. How do you deal with this? Is there a fix or replacement part to buy?

I considered it being a calibration issue too, but it was so seldom used; could still be a factor.

 

[GTA Matt]

Probably battery end cap losing connection briefly. The early handles were prone to it if you put your hand on the end of the handle at the end cap. Technically, you're supposed to put your hand on the handle where the black rubber molding is, not the end cap. If you pull too hard on an early end cap it'll lose connection and reset the wrench.

This, be sure to put no pressure near the cap when torquing. And make sure the cap contacts are clean and corrosion free.

 

[country83]

Now that you mention it, I was having problems with the end cap. It was either too tight or too loose and the wrench would have problems turning and staying on. How do you deal with this? Is there a fix or replacement part to buy?

I considered it being a calibration issue too, but it was so seldom used; could still be a factor.

Send it in to Snap-on, they'll throw a new handle on it and calibrate it for flat rate.

 

[pi_guy]

Now that you mention it, I was having problems with the end cap. It was either too tight or too loose and the wrench would have problems turning and staying on. How do you deal with this? Is there a fix or replacement part to buy?

I considered it being a calibration issue too, but it was so seldom used; could still be a factor.

They obsoleted the A model. You want tech wrenches that end the part number with a B this indicates an updated end cap.

 

[country83]

They obsoleted the A model. You want tech wrenches that end the part number with a B this indicates an updated end cap.

The B is a completely different wrench, they still service the older models and put better end caps on them.

 

[Zrexxer]

Sounds like a calibration issue to me too. 20 extra ft-lbs would only take it to 100% tolerance and 55 more ft-lbs would get you to that 125%.

Wow, epic math fail.

There's no way that 80+55 = 125% of 100...

 

[metaphysician]

The B is a completely different wrench, they still service the older models and put better end caps on them.

Where am I looking to determine the A vs B model? I'll have to check when I'm home this evening.

 

[LordPsychon]

Wow, epic math fail.

There's no way that 80+55 = 125% of 100...

Ah, I hate the metric system! You're right, should have said 45 pounds (equals 125 pounds).

 

[1950mercury]

Sounds like a POS for what snap on charges for them they should recall them or fix them for free..

 

[country83]

Where am I looking to determine the A vs B model? I'll have to check when I'm home this evening.

The regular wrenches (which I think you have) are red handled and have 4 keys. The B wrenches are all black with six buttons. Either one will have the model# on the handle on the opposite side of the screen (if it hasn't been rubbed off).

 

[mrborohachi]

The new motorcycle/bike grip (what I call them) models

 

[country83]

The regular wrenches (which I think you have) are red handled and have 4 keys. The B wrenches are all black with six buttons. Either one will have the model# on the handle on the opposite side of the screen (if it hasn't been rubbed off).

To expand on what I said earlier, there are several lines of Techwrenches:

the TECH line: just an electronic torque wrench with a red handle and 4 buttons; will only read ft-lb, in-lb, and N-m. Model number will be TECHxFRxxx.
the ATECH line: similar to the TECH line but includes angle function. Has a grey handle. Model number will be ATECHxFRxxx.
the ATECHA line: same as the ATECH but with a Dual80 head. Model number will be ATECHxFRxxxA.
the ATECHB line: completely different; with six buttons, progressive LED's on the sides (yellow, green and red), black handle; will do ft-lb, in-lb, N-m, dNm, kg-m, kg-cm, and angle (depends on model as to which units it will do). Referenced in the pic previously posted. Model will be ATECHxFRxxxB.

 

[metaphysician]

Yes, I have the black and red version with the 4 buttons. Guess I'll call Snap-On and explore this calibration/repair service option.

 

[Mohawk Dave]

I have a problem with my Techwrench too. It's the older 1/2" one, same style as Metaphysician above.

My WHOLE HANDLE is loose, it can move forward and backward on the metal shaft/handle ~1/64"+ and looses connection when it does that.

So, flat rate would include a new handle/total fix? Around $90 correct?

.

 

[country83]

Yes, I have the black and red version with the 4 buttons. Guess I'll call Snap-On and explore this calibration/repair service option.

As I suspected, your wrench has the first style of end cap that caused the problem. It will get a new handle and end cap when repaired. On the new end caps, the threads are external (versus yours where the threads are internal), there is a brass ring on both the handle and end cap for good contact, and the housing has a metal ring around the outside to prevent spreading. Works very well, actually.

 

[country83]

I have a problem with my Techwrench too. It's the older 1/2" one, same style as Metaphysician above.

My WHOLE HANDLE is loose, it can move forward and backward on the metal shaft/handle ~1/64"+ and looses connection when it does that.

So, flat rate would include a new handle/total fix? Around $90 correct?

.

Yes.

 

[Bagherra]

30ft-lbs for an oil drain plug???
What vehicle is that?

 

[metaphysician]

30ft-lbs for an oil drain plug???
What vehicle is that?

My cheap new daily driver: 2014 Hyundai Veloster Turbo

 

[metaphysician]

I think it's BS that a design flaw is on the customer to pay, but the wrench is almost 9 years old, so I guess it's time to invest in "repairing" it. I appreciate the insight guys - really wasn't sure if it was a calibration issue or user error, so this definitely helped.

 

[Mohawk Dave]

I think it's BS that a design flaw is on the customer to pay, but the wrench is almost 9 years old, so I guess it's time to invest in "repairing" it. I appreciate the insight guys - really wasn't sure if it was a calibration issue or user error, so this definitely helped.

That's the way I feel too. Snap On has excellent CS and b/c of that I'm not complaining. They've taken care of stuff that probably shouldn't have been. Or at least my driver did.

If the TW failed due to wear and tear, great, it should be on us. But a design flaw, albeit, a long term one, is still a design flaw.

 

[Fcvapor05]

I have the older model tech wrench (x3, all three sizes) and have torqued literally thousands of fasteners (okay, maybe hundreds with the 1/4") without issue.

People need to learn to pull the wrench on the handle, not on the end. Where you put your hand doesn't affect the amount of torque applied. Move your hand away from the end cap and this problem goes away.

 

[metaphysician]

I may have misspoke earlier - I only have my hand on the handle, just below the LCD, not the end cap. I knew I was having problems if I screwed the end cap on too tight or too loose, so I stayed away from the cap once the wrench turned on.

I called and they sent me a prepaid label to return the wrench and pay the $85 flat rate repair/calibration service.

 

[purplezr2]

I have the older model tech wrench (x3, all three sizes) and have torqued literally thousands of fasteners (okay, maybe hundreds with the 1/4") without issue.

People need to learn to pull the wrench on the handle, not on the end. Where you put your hand doesn't affect the amount of torque applied. Move your hand away from the end cap and this problem goes away.

Actually it does! The further point from the socket will be the easiest to apply force to reach a desired torque.

 

[country83]

Actually, position of hand will make a difference in how most torque wrenches read/click. Moving the hand farther down the handle (away from the drive square) will in most cases drive the applied torque readings down, and moving the hand closer to the head will raise the applied torque.

 

[Fcvapor05]

Actually, position of hand will make a difference in how most torque wrenches read/click. Moving the hand farther down the handle (away from the drive square) will in most cases drive the applied torque readings down, and moving the hand closer to the head will raise the applied torque.

Physics disagrees with you.

If you move your hand down the handle, closer to the socket, you will have to apply more effort to reach a given torque reading, but when the wrench clicks the torque being applied to the fastener is the same.

 

[country83]

Physics disagrees with you.

If you move your hand down the handle, closer to the socket, you will have to apply more effort to reach a given torque reading, but when the wrench clicks the torque being applied to the fastener is the same.

No it is not. Most torque wrenches rely on the position of the hand to determine when the proper amount of torque has been applied. The reasons are complex, but I'll try to simplify it the best I can.

Most torque wrenches don't actually read applied torque, they actually read applied force at a specific distance. This is because the reaction element that actually "clicks" or otherwise registers the torque is actually offset from the square drive. So when you move your hand (or, God forbid, you use a pipe!) on the handle, it changes how much force is applied to the reaction element. This, in turn, changes how much torque is actually applied to the fastener. So, moving the hand farther away from the square drive increases the amount of force applied to the reaction element without increasing the torque actually applied to the fastener, making the wrench "click" at a lower applied torque.

This also applies to electronic torque wrenches like the Techwrenches this thread started off talking about, as the reaction element is offset from the square drive on those as well.

It's crazy, I know, but I've seen it many times on the testers at work how hand position changes torque readings.

 

[Davie]

I wish I was gentle enough to justify buying one of these. I work in a busy heavy vehicle garage and it'd get killed in no time . I'll stick to my CAT Torque wrenches

 

[Fcvapor05]

No it is not. Most torque wrenches rely on the position of the hand to determine when the proper amount of torque has been applied. The reasons are complex, but I'll try to simplify it the best I can.

Most torque wrenches don't actually read applied torque, they actually read applied force at a specific distance. This is because the reaction element that actually "clicks" or otherwise registers the torque is actually offset from the square drive. So when you move your hand (or, God forbid, you use a pipe!) on the handle, it changes how much force is applied to the reaction element. This, in turn, changes how much torque is actually applied to the fastener. So, moving the hand farther away from the square drive increases the amount of force applied to the reaction element without increasing the torque actually applied to the fastener, making the wrench "click" at a lower applied torque.

This also applies to electronic torque wrenches like the Techwrenches this thread started off talking about, as the reaction element is offset from the square drive on those as well.

It's crazy, I know, but I've seen it many times on the testers at work how hand position changes torque readings.

ALL torque wrenches measure applied load at a distance. 'torque' is a value derived from an equation, and is not possible to determine from any direct measurement, by definition.

The only way to apply more torque once a mechanical wrench has clicked is to bottom out the mechanism, which is something I've seen a lot of people do anyways when they are rushing jobs. The length of the body of the torque wrench doesn't matter- they are sized to be small enough to store conveniently, and large enough to enclose the mechanism and provide a long enough moment arm that a normal human can operate the tool within it's designed range, but that's it. Put a cheater on the end of a click type torque wrench at any setting, and torque a fastener until the wrench clicks, without bottoming out the mechanism, and the torque applied to the fastener will be EXACTLY the same as the torque applied to the fastener using the same technique with no cheater in place. This is counter-intuitive to some people but it's a very simple physics problem.

 

[country83]

Put a cheater on the end of a click type torque wrench at any setting, and torque a fastener until the wrench clicks, without bottoming out the mechanism, and the torque applied to the fastener will be EXACTLY the same as the torque applied to the fastener using the same technique with no cheater in place. This is counter-intuitive to some people but it's a very simple physics problem.

Wrong. Actually a cheater would drive the applied torque lower at the square drive. This is because it would increase the leverage on the reaction element. The reaction element is calibrated to click at a certain applied FORCE, not torque. The fact that it is offset from the square drive is what generates the torque. Making the lever arm longer increases the force on the element, making it click sooner than it's calibrated to. This makes it click at a lower reading than it normally would.

Unless you've seen the change of readings on a calibrated tester by simply moving the tester arm on the handle like I have, it makes no sense. But what I say is true. Why else would they tell you to hold the center of the handle when using one?

 

[Skin]

I have the older model tech wrench (x3, all three sizes) and have torqued literally thousands of fasteners (okay, maybe hundreds with the 1/4") without issue.

People need to learn to pull the wrench on the handle, not on the end. Where you put your hand doesn't affect the amount of torque applied. Move your hand away from the end cap and this problem goes away.

The battery compartment, which happens to be IN the handle, warps. That's a big part of the issue. Its a very poor design that Snap-On/CDI addressed in the updated B model. Thanks for your snobbish disregard anyway.

 

[country83]

The battery compartment, which happens to be IN the handle, warps. That's a big part of the issue. Its a very poor design that Snap-On/CDI addressed in the updated B model.

They also upgraded the replacement housings for the older models to a MUCH better design that pretty much eliminates the power loss issues.

 

[bob_the_builder]

Maybe a little off topic but to the Techwrenches need to be reset to zero when you are done with them or can you just set them down and they reset and turn off on their own?

Bob

 

[DodgeMech]

only thing to be done with them is when done for the day(or week or month) is to put it up in its case, with the batteries out

 

[Bagherra]

I still can't get over 30ft-lbs for an oil drain plug....

 

[2004.5cumminsman]

Save yourself the headache man, get rid of it! I jumped ship and bought the set thinking they are great! Wrong!!! Same issues, they don't like service trucks due to vibration, when working out in the field rain is your enemy on them! Sell them and buy click type and not have issues. Snap on is great for some things, but anything they sell that requires battery's ****!