Torquing Lug Nuts - Overrated?

Kurb

Well-Known Member
#1
Of course you are supposed to torque your lug nuts....

For many years, I never did, until now. This time, I thought I would do it right. The result was a broken lug.:eek: The lug was nearly brand new since I recently replaced both front hubs. For that job, I did manage to torque the hub bolts and axle nuts without issue.

I figured out today the main cause for the broken lug was an out-of-spec torque wrench. I have two torque wrenches with different ranges, and the one that broke the lug was breaking away at a much higher torque than the other wrench. I ran a test, and the good wrench (at least I think is the case) was at 50 ft-lb to move a lug nut tightened to 35 ft-lb by the bad wrench. I then set the bad wrench to 45 ft-lb and rotated the lug nut without the bad wrench breaking away. This time, I did not push my luck and stopped turning the nut before the wrench clicked.

I normally only use my torque wrenches when fluid seals are involved and for some of the more critical higher torque joints, such at the axle nut. Lug nuts would have fit the bill except that I had tightened lug nuts without issue for years before I owned a torque wrench. The last set of rotors developed a slight pulsation during heavy braking in less than a year, which could be caused by uneven lug nut torque, so I decided I would use the torque wrench with the new rotors. Not only did it take much longer to install the wheels, the first lug on the second wheel snapped off.

My old process was to put a little bit of penetrating oil on the lugs and tighten them as much as I could with a four-way lug wrench. It has worked for many years without issue. I decided to go back to that for now.

I'm curious. Are there are a lot of people out there not torquing lug nuts without problems? For those of you that do torque them, how often do you get your torque wrenches calibrated, and are there any special tricks to avoid breaking lugs (or other bolts)? I noticed that the lug nut seemed to be turning more than it should have, so maybe there is a rule of thumb for how far you should turn the nut past snug-tight before you suspect a torque wrench issue? Glad this was a lug nut and not something threaded into the block.:thumbsup:
 

Mektek

Well-Known Member
#2
I use a harbor freight AC electric impact wrench. I don't use a torque wrench at all. There are some super powerful pneumatic impact wrenches that can cause problems, but this electric is just about right for lug nuts. Fast way to do it......
If you broke a nut or stud, it was defective and not because you overtorqued it. I think the official spec is 109 ft/lb - so you under tightened it.
Rotor damage can only be caused by gross abuse - like the 450 ft/lb pneumatic guns can do.
 

northcreek

Well-Known Member
#3
You could use a "torque stick" that is rated for your application. A lot of garages use them, they're not as accurate as a torque wrench but, close enough for lugs.
 

Reprise

Lifetime VIP Supporter
#4
I do torque my lugs (as an aside, what vehicle do you have that could possibly have only a 50 ft/lb spec, not to mention a 35?) I've never seen a passenger car with less than an 80ft/lb spec - and our 360s are spec'd at 105, IIRC.

When I used to track my S2000, I would check torque before / after the first couple of runs - and there were many out there with me doing the same thing. Cheap insurance, if you will.

Anti-seize compound might help w/ the lug bolts. Since it's good to use on the inner wheel / outer hub surface, a swipe on the lug threads couldn't hurt. I've used it on mine, which also have some 'snug' threads. Speaking of which - if those threads have corrosion, take a wire brush and give them a good going-over. Then follow up w/ the anti-seize.

If you're worried about having the lug nuts loosen due to the anti-seize - don't. Just don't lather it on like a pre-teen girl or elderly lady applies makeup (w/ a trowel...lol)

I also torque most bolts w/ a listed specification, unless the spec is between 10-15 ft/lb and it's for something non-critical, because I trust my sense of feel with that small amount. Call me anal-retentive.

'Calibration' for me happens when I take a torque wrench back to HF for warranty replacement. Since I only use them to work on my own vehicles, they never see enough usage to go out of spec, to be honest - and I don't toss them around. They are placed back in their case after use, after releasing the tension on the internal spring (and then reapplying about 5lb worth, per manufacturers instructions)

I *did* have one lose one of the small screws fastening the lever / mechanism - and trying to fix it, screwed it up. No worries - they carry a lifetime warranty. For around $15-$20, depending on size (they're always 'on sale') - you really can't beat them.
 
Last edited:

Dr.Fiero

Well-Known Member
#5
Funny thing on "new" tech.
I have at least 6 torque wrenches. I took them all into a buddy who has a calibrated/certified testing machine. He ran all of them through.
They were all within tolerable spec except for one (tossed it), but of all of them - the MOST accurate one was one of my beam deflection ones from the 1940's (that's what era he figured anyhow).

All of my beams ranked the highest in accuracy, vs my clicks.

So - something to be said for old tech! :biggrin:
 

Reprise

Lifetime VIP Supporter
#6
I've heard that the old-style beams will generally be more precise than the clickers, especially for run-of-the-mill tools. Thing is, though - I will tire my arm out holding that beam in position making sure that it's *exactly* on 80 ft/lb, for example (since this started re: lug nuts). With me, '79' isn't enough, and '81' is 'too much' (which is why we use them, I suppose...lol).

Yep, I'm the type that if I had visibly tightened something 1 ft/lb too tight, I'd loosen the bolt and retighten (which means putting the beam down, and picking up the ratchet again, since a beam can't be used to loosen (at least mine couldn't.) And that's when I was younger & stronger. And dumber, obviously... :laugh:

Yes, I know you're not supposed to loosen bolts with a TW, as it can affect the aforementioned calibration - but if that is really the case, why do so many manufacturers include the reversing lever on the clicker-type wrench? Should we call that the 'screw it' lever? LMAO


Didn't take me long to give in and get a 'sloppy' clicker to replace it...LOL I still have the 1/2" beam wrench, somewhere.

I've never had a failure resultant from using the clickers, either way (from being 'too tight' or 'too loose'), so while 'precision' may be called for, 'absolute' precision...isn't - ? LOL At least not in our world of automotive maintenance / repair, most of the time.
 
Last edited:

Wooluf1952

Well-Known Member
#7
The TW can also be used to torque Left hand threads. I think the bigger damage would be using a TW as a breakerbar.
 

Dr.Fiero

Well-Known Member
#8
^^ Correct - the idea is not to "beat on" the poor thing, or go over it's intended range.

As for the beam vs. clicker -- would you rather get a free workout, and nail them pretty close. Or would you rather hear your unit go click... and it may or may not be +/- 10 lbs anyhow? Unless you get your wrench calibrated every 6 months (yes, I've worked in places that require it!), you'll never know.

As for the 79/80/81 lbs, that's more than within the acceptable tolerances range anyhow! Of course, every fastener is different.
 
#9
I've been using my clicker Craftsman for years and haven't had a wheel fall off yet...
 
#11
It was pretty close when I tested it against a torque stick about 4 years ago lol.

My lug nuts on my truck call for 140 ft lb. Good thing not any higher, the wrench only goes up to 150.

I have a Tekton 3/8 torque wrench also that I used when reinstalling rocker arms on my Camaro. Only 23 ft lb, and they haven't popped off yet either lol. They do have red threadlocker on them however.
 
#12
Well with the beam as long as you don't stress it to the point where it begins to yeild you can stress it an indefinite amount of times (roughly) and it'll take about the same amount of force to do it. You know the material properties, measure the distance and applied force for the elastic deformation and it'll about be right. The springs in the clickers wear out faster because it isn't a constant force... the only problem is that a clicker is way more convenient in those shitty spots where it usually actually matters. I use the beam to test the clickers and hold the belt tension. They're great.
 
#13
I can say that I have had wheels almost falling off a long time ago when I would use just my air impact on my old Montana van. Was hearing noise from a wheel on a trip and had lost some nuts and the ones still there were loose. When I retightened them, a couple of the studs broke. Borrowed a nut or two from other wheels so I had at least 3. It happened a second time on another day. I think it was caused by a failing impact that wasn't giving a lot of torque when tightening.

For torque sticks, they seem to work with caveats. I saw this video a while ago and seems to say they can be good and bad depending on the sockets and impact used.


Of course, torque wrench, clicker or beam, is the best. If I had torque sticks, I'd use one one lower then the one required and finish with a torque wrench.
 

northcreek

Well-Known Member
#14
The drift of this thread seems to be that you can/can't trust torque sticks, impact guns and torque wrenches. For years I used an impact gun with judgement and never had a problem. Now I'm all anal with a clicker T-wrench with no problems. So I guess no matter what method you use, a good sense of feel will be required. Most of us long time wrenchers know what a properly tightened lug/bolt is supposed to feel like, RIGHT?
FTR I asked my tire shop what they use and they use good quality (not HF) torque sticks.
 
OP
OP
Kurb

Kurb

Well-Known Member
#15
I do torque my lugs (as an aside, what vehicle do you have that could possibly have only a 50 ft/lb spec, not to mention a 35?) I've never seen a passenger car with less than an 80ft/lb spec - and our 360s are spec'd at 105, IIRC.
Just to clarify, the low torque values were my post failure test. When I broke the lug, I was using the torque value listed in the Haynes manual, which was 103 ft-lb.

The test showed a delta of 15 ft-lb between the two torque wrenches. Assuming the lower torque wrench was bad and the percent error was the same at higher values, this means that the bad wrench would have applied nearly 150 ft-lb. The stud looked elongated as if if failed due to excessive preload, and it did feel like I turned it more than I should have before it broke.
 
Last edited:
OP
OP
Kurb

Kurb

Well-Known Member
#16
Anti-seize compound might help w/ the lug bolts. Since it's good to use on the inner wheel / outer hub surface, a swipe on the lug threads couldn't hurt. I've used it on mine, which also have some 'snug' threads. Speaking of which - if those threads have corrosion, take a wire brush and give them a good going-over. Then follow up w/ the anti-seize.

If you're worried about having the lug nuts loosen due to the anti-seize - don't. Just don't lather it on like a pre-teen girl or elderly lady applies makeup (w/ a trowel...lol)

.
Won't anti-seize reduce the thread friction and increase the preload for the specified torque values, which normally apply for dry installation?
 
#17
Won't anti-seize reduce the thread friction and increase the preload for the specified torque values, which normally apply for dry installation?
Dry threads are torqued higher. Yes.
 
#18
You probably weakened your studs from driving on under-torqued nuts. Properly torqued nuts pulls the wheel against the hub and no lateral pressure is put on the studs. Over torqueing can cause rotor issues I've been told. I don't believe in impact guns.
 
OP
OP
Kurb

Kurb

Well-Known Member
#20
You probably weakened your studs from driving on under-torqued nuts. Properly torqued nuts pulls the wheel against the hub and no lateral pressure is put on the studs. Over torqueing can cause rotor issues I've been told. I don't believe in impact guns.
I have been working on cars for over 25 years without torquing lug nuts, and my first time using the torque wrench on the lug nuts was the first time I ever broke a lug tightening it. Based on my test, I know that the torque wrench put too much torque on the lug and snapped it off. I am pretty sure this had nothing to do with under-torquing.
 

JerryIrons

Well-Known Member
#21
I use my clicker torque every time, which hasn't been calibrated once in the 25 years I've owned it, so I have no idea how accurate it is anymore. Not only that, but since I live near Buffalo, NY I use antiseize on my threads, and then go 15% under the torque value specified. So if it's 100 ft lbs recommended torque, on anti-seize threads I'll go to 85. I remember reading somewhere how antiseize causes you to overtorque by about 15 % or so.

Only time I ever ran into trouble is when I lowered the vehicle, and forget to final tighten the lug nuts. A wheel didn't fall off, but it started making strange noises and fortunately I pulled over to look it over. Been paranoid about it ever since.
 

MRRSM

Lifetime VIP Supporter
#22
@Kurb ... I'd be curious to know whether you are the original owner of your SUV... as GOK (God Only Knows) what Prior Owners will do with them mechanically from time to time. Check out Post #20 in my "Spun Stud Rescue" Thread as the YVOP (Youtube Video Original Poster) IMSTRICKEN06 ...has an entertaining and informative video on this very subject matter:

https://gmtnation.com/forums/threads/need-a-spun-stud-rescue.14566/#post-509466
 
Last edited:
OP
OP
Kurb

Kurb

Well-Known Member
#23
I am not the original owner, but I bought it in 2008 with ~42K miles on it. With over 210K on it now, I might as well be the original owner. The lugs were nearly brand new since I recently replaced the front hubs. Thanks for the info. I don't have time at the moment, but I'll check out the videos when I get a chance.
 

16vcabman

Well-Known Member
#24
I do torque my lugs (as an aside, what vehicle do you have that could possibly have only a 50 ft/lb spec, not to mention a 35?) I've never seen a passenger car with less than an 80ft/lb spec - and our 360s are spec'd at 105, IIRC.

When I used to track my S2000, I would check torque before / after the first couple of runs - and there were many out there with me doing the same thing. Cheap insurance, if you will.

Anti-seize compound might help w/ the lug bolts. Since it's good to use on the inner wheel / outer hub surface, a swipe on the lug threads couldn't hurt. I've used it on mine, which also have some 'snug' threads. Speaking of which - if those threads have corrosion, take a wire brush and give them a good going-over. Then follow up w/ the anti-seize.

If you're worried about having the lug nuts loosen due to the anti-seize - don't. Just don't lather it on like a pre-teen girl or elderly lady applies makeup (w/ a trowel...lol)

I also torque most bolts w/ a listed specification, unless the spec is between 10-15 ft/lb and it's for something non-critical, because I trust my sense of feel with that small amount. Call me anal-retentive.

'Calibration' for me happens when I take a torque wrench back to HF for warranty replacement. Since I only use them to work on my own vehicles, they never see enough usage to go out of spec, to be honest - and I don't toss them around. They are placed back in their case after use, after releasing the tension on the internal spring (and then reapplying about 5lb worth, per manufacturers instructions)

I *did* have one lose one of the small screws fastening the lever / mechanism - and trying to fix it, screwed it up. No worries - they carry a lifetime warranty. For around $15-$20, depending on size (they're always 'on sale') - you really can't beat them.

I guess if you don't torque antisieze is just fine NOT. Antisieze reduces friction which will allow you to over torque with a torque wrench. Now add a impact and you may have some real fun getting these off on the side of the road with tools supplied. The torque on the wheels is 100 ft. lbs. do not use antisieze on lugs. great for rust prevention between wheel and brake drums/rotors and also on hub. Have fun as always!
 

northcreek

Well-Known Member
#25
This thread is going nowhere so : Everybody has to buy these....
now, all you need is a F'n hammer :2thumbsup:
nla-tra-547-pic1.jpg
 
Last edited:
OP
OP
Kurb

Kurb

Well-Known Member
#26
@Kurb ... I'd be curious to know whether you are the original owner of your SUV... as GOK (God Only Knows) what Prior Owners will do with them mechanically from time to time. Check out Post #20 in my "Spun Stud Rescue" Thread as the YVOP (Youtube Video Original Poster) IMSTRICKEN06 ...has an entertaining and informative video on this very subject matter:

https://gmtnation.com/forums/threads/need-a-spun-stud-rescue.14566/#post-509466
Great tool! The torque adapter looks like a good way to check torque wrenches for only $29. I am going to have to make a trip to Harbor Freight.
 
Top Bottom