Torque Wrench help

[John316]

We are looking at getting a torque wrench for the bus lug nuts. The question is which one? What kind of quality (HF, Snap On, Matco, Napa???)? Clicker style, or lever style?

Any help would be much appreciated.

Thanks,

God bless,

John

[bevans6]

There are two ways to go on this, in my view.  Good, better, best are the choices, best is out the window because they are truly expensive.  I went with "good" - a higher priced unit from Princess Auto, 600 ft lbs, reversible (more later), with a calibration sheet, so far very satisfactory - repeatable, and no issues.  "Better" is the wrench I was borrowing for a while - Snap-On, fitted oak case, all of that.  Both 3/4" drive.  Mine cost about $350, the Snap-On was probably $1,000.

I recommend click type.  Dial or lever type are arguably more accurate, but accuracy isn't the ultimate  goal here, repeatability to within around 5% is the goal.  Reversibility is obviously key if you have right and left hand threaded lugs.  Many lower priced torque wrenches in the 3/4" drive, 600 ft-lb range are not reversible, even it they have a reversing ratchet head - they only measure torque in one direction.  Something to definitely watch out for, and the sales guys in stores that sell them don't know.  My torque wrench is reversible - by removing the whole ratchet head from the wrench (two Phillips head screws) and installing it from the other side.  Unwieldy, but it works.  The Snap-On worked both ways just by flipping the lever on the ratchet head.

You can use a smaller torque wrench for high torque applications by making an extension for it.  If you have a 200 ft lb wrench that is 18" from socket to handle, it you extend that by 36" you have a 600 ft lb torque wrench.  Not sure I would actually do that, though, but it's perfectly legitimate.  A good source of "better" and "best" quality torque measuring stuff is here - http://www.torqwrench.com/  If you look closely, you might notice that Snap-On gets some of their stuff here.

Brian

[kyle4501]

Brian got his in while I was typing. His information is good, but to add my opinion:
With all the people & tire shops banging wheels on with impact guns & absolutely no regard for actual torque applied, you'd think you'd see more wheels falling off if torque accuracy was really so important.

However, that is not the only failure mode - warped hubs, stretched & broken studs, enlarged stud holes in wheels, etc are also failures.
I believe the reason for minimum specified torque required is to keep it securely attached to the vehicle.
I believe the reason for maximum specified torque allowed is to prevent or minimize damage to the stud, hub, wheel or nut.

Due to the nature of the specified dry torque for wheel lug nuts, consistency between individual nuts isn't likely to be that good. After all, torque is actually only an inference of the actual clamping force applied to the wheel.
So, the best we can do is get 'em tight enough while hoping we didn't go too tight.

A clicker type is easier to use.
But, deflection beam types are most consistently accurate & don't need re-calibrated as often. They are easily checked to verify calibration - just look at the pointer when unloaded - is it at zero? Is the beam bent or otherwise damaged? See, simple.
But, the deflection is difficult to read when you are quaking & quivering trying to hold it steady under a strain.  

Cheaper & easier is to get a wrench with a long handle (for special use on the wheels) and a bathroom scale. While standing on the scale with your hands 3 feet away from the axis of rotation (socket extension) & the handle parallel to the ground - push down until the scale reading is 150# less than when you started. You will have 450 foot pounds of torque on the nut (3 feet * 150 pounds).

[bevans6]

My word, we are (I am, at least) tool nerds!  Here is the classic beam torque wrench:  http://www.srtorque.com/tabeam.html

I bought one on ebay because I thought it looked cool, 2400 inch-pounds which sounds a lot until you realize it's only 200 ft lbs.  It takes a lot of skill to use, and it's too long to fit in any of my tool chests, so I have it displayed on a wall....

[kyle4501]

My word, we are (I am, at least) tool nerds! 

The only thing better than more tools is knowing how to use them (That's what she said  ).   

[lostagain]

I put my body weight (170lbs) 3 feet out on the bar. That applies 510 lbs/ft of torque. A lot more accurate than most tire shop's 1" air guns. You don't need an expensive torque wrench.

JC

[trucktramp]

As a fellow tool nut I have to agree with Kyle and Bevans.  Get a clicker type.  Name tools are likely better than the el cheapo ones (or in this case more accurate).  Belle tire is the only place that I have ever seen use a torque wrench on heavy truck tires.  Everyone else just blasts them on with an impact gun.  I can say that I have had a wheel come off on two different times.  The lugs loosened up and the center of the rim fractured.

If you know buy your own torque wrench remember to reset it to zero when you are done.  It will keep the accuracy longer.  Eventually though, you will need to have it recalibrated and your friendly tool man can help you with this.

[luvrbus]

John, go with clicker type if you must and buy a`Proto brand everybody copies theirs 



good luck

[eddiepotts]

You can use a smaller torque wrench for high torque applications by making an extension for it.  If you have a 200 ft lb wrench that is 18" from socket to handle, it you extend that by 36" you have a 600 ft lb torque wrench.

I do not think this is true. Now if you put a load of 200# out 12" from the socket you get 200#. If you put 200# out 24" you will get 400# but, if you are use the clicker type wrench you are measuring the force at the ratchet head. It does not matter how long you make the handle it will still register the head. It will still click at set point no matter how long of a cheater you put on it. I am not trying to correct anybody here it is just a scary thought for someone to try.

[TomC]

Just remember-if you use the click type, you can continue to go further once the click is heard.  How many of us will give it just a little bit more to make sure?  Good Luck, TomC

[kyle4501]

Good point of caution, but "the math don't lie".
An indicated 200 ft-lbs on an 18" (18" = 1.5ft) torque wrench provides ( 200lbs/1.5= ) 133.3 lbs of force on the wrench handle (That is 18" from socket center to middle of the handle).
Now, you add a 36" extension (Not cheater bar) to the socket end (NOT THE HANDLE END) - then you will have 3 feet + 1.5 feet = 4.5 feet from the socket center to the middle of the handle. 133.3 x 4.5 = 600 foot pounds.

(edit to add) For the extension mentioned here, Brian & I aren't talking about the round bar that the puts the socket axially further from the drive head, but rather a stout flat bar with a square hole at one end for the torque wrench drive to engage & 36" away there is a square shaft sticking out to drive the socket. Thereby increasing the radial distance from socket to wrench handle.

You can use a smaller torque wrench for high torque applications by making an extension for it.  If you have a 200 ft lb wrench that is 18" from socket to handle, it you extend that by 36" you have a 600 ft lb torque wrench.

I do not think this is true. Now if you put a load of 200# out 12" from the socket you get 200#. If you put 200# out 24" you will get 400# but, if you are use the clicker type wrench you are measuring the force at the ratchet head. It does not matter how long you make the handle it will still register the head. It will still click at set point no matter how long of a cheater you put on it. I am not trying to correct anybody here it is just a scary thought for someone to try.

[kyle4501]

http://buy1.snapon.com/PRODUCTS/TORQUE/pdf/techwrench/TECHWRENCH%20INTERNET%20SITE.pdf

Go to the last page (9). They explain it better than I can.

[eddiepotts]

Yes that make since. if you add an extention from the ratchet head to the fastener it will install a higher torque to the fastener. I just did not want someone to put a cheater on their torque wrench thinking the were putting more on the fastener than they were.

[mikelutestanski]

HELLO:    I use a 4 foot torque wrench clicker type anytime wheels are involved. Lately I have to resort to the rattle gun for the first two rounds then finish off with the torque wrench   It gets harder as my age progresses.   THe reversible head works well.  A bit of a pain.
    I refuse to say anymore because of prior experiencessss.   
      Regards and happy busssin    mike

[John316]

Thank you, folks.

It looks like we won't be able to afford a Snap On, Matco, or Proto. They all have one year warranties, though. However, we will be purchasing a Carquest Gearwrench brand clicker style wrench. That seemed to be the mid range area, at $450.

Thanks again for the info. I learned a lot from this thread.

God bless,

John