Torque wrench on lug nuts?

[John K Jordan]

Does anyone else use a torque wrench on lug nuts? It drives me crazy to see the help in the tire shop pounding repeatedly with the pneumatic impact wrench, no clue about what the wrench is set to and not even following the recommended tightening sequence. When I ask they say don't worry, the wrench is set right but when I torque by hand when I get home they are almost always over-tightened.

I bought a used slant-load horse trailer recently, tandem axles, six lugs each wheel. I cleaned the exposed threads, lubed, and removed the lug nuts. They were so tight some took a lot of pounding with my impact wrench just to remove, some tight all the way to the end. It turned out each lug nut was horribly distorted from over-tightening and some wouldn't even go back on the studs gracefully. I had to use a thread restorer to "retap" some of the nuts and clean up the ends of some studs just to get them back on.

The next day I bought all new lug nuts and installed them with a manual torque wrench in three steps as recommended, rechecked after driving some. I was headed out for a 22 hr drive and wanted everything right (also repacked the wheel bearings and cleaned/lubed/repaired rusty brake hardware.) Tires were overinflated too, according to the mfgrs recommendation.

I think I'm less stressed when I jack up and take the wheels off the vehicle or trailer myself and throw them in the truck; let the shop mount the and balance the tires, I'll put them back on.

End of rant...

JKJ

[Kev Williams]

"Don't worry," -- those two words are right up there with "Watch this-" ... Personally, I can't remember the last time I DIDN'T see a 'tire technician' using a torque wrench to finalize the nut torque. (but it was likely in the 1970's!)

[Marc Fenneuff]

Years ago my future wife rented a car and upon returning it, the rental place noticed 3 studs were broken off of the DS front wheel. Guess who got the bill.

Then there was the time a couple years ago when I struck a deer and had a body shop replace the front bumper, bumper cover, and fender. Shortly afterwards I found out every one of the fasteners in the bumper cover had been over-torqued, thereby shredding their plastic nuts.

Moral of the story: None of these guys seem to care.

Agree that a shop over-tightening the lug nuts is a safety issue. I rotate my own tires and am aware generally of the torque I'm applying since I know what my impact wrench is set at.

[Paul F Franklin]

I always use a torque wrench. Over-tightening or uneven-tightening can not only damage the studs, it can warp the rotor on disk brakes. I mostly do my own service, but if it comes back from the shop for something that required r/r tires, I always check and they are always over-torqued.

As for the wrench being "set right"...HA!

[Scott Winners]

Since I started checking around the turn of the century, every shop that has tightened my lug nuts has overtightened my lug nuts.

Where ever possible I takes rims to the tire shop for new tires, and then deal with the lug nuts myself with my torque wrench.

[Anuj Prateek]

I use torque wrench whenever I change tires. Before I bought spare set of wheels for winters I used to go to a tire shop. They used torque wrench as well.

Also, after driving 100-150KM after tire change, it's a good idea to retorque the nuts.

[Curt Harms]

Years ago my future wife rented a car and upon returning it, the rental place noticed 3 studs were broken off of the DS front wheel. Guess who got the bill.

Then there was the time a couple years ago when I struck a deer and had a body shop replace the front bumper, bumper cover, and fender. Shortly afterwards I found out every one of the fasteners in the bumper cover had been over-torqued, thereby shredding their plastic nuts.

Moral of the story: None of these guys seem to care.

Agree that a shop over-tightening the lug nuts is a safety issue. I rotate my own tires and am aware generally of the torque I'm applying since I know what my impact wrench is set at.

It's also a PITA when you have to change a tire on the shoulder of a busy 4 lane road at night - in the rain - and the lug nuts were installed using the "let 'er rattle 'til she stops" method. At least in Pennsylvania vehicles have to be inspected annually. Part of that inspection is checking brake condition which involves removing all 4 wheels. After inspection I loosen the lug nuts then retighten to a reasonable torque setting. I can get the nuts off using the manufacturer provided wrench if need be.

[Tom M King]

I use torque wrenches for many things, even putting lawnmower blades on. Different torque wrenches for different jobs, like that mower blade nut that's taken off with an impact driver, but tightened with an old beam type torque wrench so there is nothing to have to release spring tension on after use. The correct sized socket stays on it, and close at hand where I change the blades.

[Erik Loza]

“Yes” + apply anti-sieze paste to all threads as well as backs of wheels.

Erik

[Jack Frederick]

I bought tires for my wife’s car a few years ago. New tires can absolutely transform the way a car drives. Well, they should. I accepted or expected that the wheels would be mounted and balanced correctly, but I rarely drove the car. After a couple of thousand miles I was out on the hwy and it just did not feel right. I took the car back in and asked to check the balance. All four wheels were off. I still do business with the shop but when I come in the owner tells me he will make sure it is correct. It all depends on the guy on the end of the wrench.

[Mike Kees]

My local tire shop was where I figured out that tires should be installed and torqued to specs for that vehicle. I got a list of torque specs for all of my vehicles from them.

[Edward Weber]

Does anyone else use a torque wrench on lug nuts? It drives me crazy to see the help in the tire shop pounding repeatedly with the pneumatic impact wrench, no clue about what the wrench is set to and not even following the recommended tightening sequence.

JKJ

Irritates the ____ out of me also but your comment is equally at home with those who use battery powered drills and impact drivers for EVERYTHING.

[Roger Feeley]

"Don't worry," -- those two words are right up there with "Watch this-" ... Personally, I can't remember the last time I DIDN'T see a 'tire technician' using a torque wrench to finalize the nut torque. (but it was likely in the 1970's!)
Don't forget “Hold my beer.” and “This is going to be really cool.”

[Roger Feeley]

Which torque wrench is best:
the long needle
dial
click

[Mike Henderson]

I had a flat tire on the highway and couldn't get the lug nuts off. A cop stopped to check on me and he couldn't budge the lug nuts either. I had to wait for AAA to come with an impact wrench.

Mike

[Bill Dufour]

Which torque wrench is best:
the long needle
dial
click
The beam type is never going to go out of calibration if not overloaded with a cheater bar. A click type is easier to use and read but is supposed to be recalibrated periodically and the spring released every night.
Bill D

[Alex Zeller]

If they are using an impact wrench they should be using torque sticks. I've never bothered to get a set so I use a torque wrench.

https://www.youtube.com/watch?v=glWZIuJWaWg&ab_channel=dial2fast

[John K Jordan]

Which torque wrench is best:
the long needle
dial
click

I have some of each. I like the click type for places where it’s difficult to lean down and watch the indicator while applying force. For lug nuts I’ll set the first one with the beam type then set the click wrench to match.

[Lee DeRaud]

I like the click type for places where it’s difficult to lean down and watch the indicator while applying force.
Or as I call it, "everywhere". :)

Just once I'd like an easy job, all on the top side of the engine...

[Paul F Franklin]

There seems to be debate about putting lube or anti-seize on wheel studs. My Ranger manual says not to apply anything to the studs. Apparently the torque values are based on dry, clean, bare metal. The lube or anti seize reduces friction and results in over-tightening. Others out there disagree. Personally, I wire brush the studs and leave them dry, but I do put anti-seize on the area of the wheel that bears on the hub. Probably best advice is to follow manufacturers recommendation.

[roger wiegand]

The places I go for service use an air impact wrench to get them off and a hand torque wrench to put them on. At my normal garage they use the torque wrench on everything as far as I've noticed. They work mostly on vintage European vehicles with repair work like mine to fill in/pay the bills. Always fun to go there to see what's being refurbished.

[fritz eng]

I only buy my tires at Costco. One price for installation, balance, and nitrogen fill. They always use a torque wrench for final tightening. My last purchase in February had a reminder to return 6,000 miles later for rotation and torque. The price also includes puncture repair for the life of the tires. What a deal!

[Edward Weber]

The places I go for service use an air impact wrench to get them off and a hand torque wrench to put them on. At my normal garage they use the torque wrench on everything as far as I've noticed. They work mostly on vintage European vehicles with repair work like mine to fill in/pay the bills. Always fun to go there to see what's being refurbished.

Having worked as a mechanic for many years (heavy trucks primarily) there is a place for every tool.
I used impact guns quite a lot but they have their place and attaching wheels is one of them but you don't just blast until it stops turning. They have regulators on them.
You can run up the wheel nuts and/or studs and then torque if you feel it necessary for the particular piece of equipment. Over tightening can do lots of damage to the studs, by stretching them, damaging threads, fatiguing the metal or even breaking them clean off, not to mention what it does to the rim.
The wheels I worked on were, for the most part steel and could tolerate an occasional over tightening by a lower skilled mechanic without too much damage to the wheel.
Today's cars and trucks use many light weight alloys and are very easily damaged by a monkey with an impact gun.
It''s simply not that hard, use the right tool for the job and everything will work out fine.

I would never apply any anti seize type product to a lug nut/stud. Any introduction of friction modifying chemical will skew the measured amount of applied torque. With the addition of lubrication you will inadvertently over torque the nuts/studs. It is not necessary

[Erik Loza]

With the addition of lubrication you will inadvertently over torque the nuts/studs.

That has not been my experience over 20+ years/countless vehicles.

Erik

[Ole Anderson]

Any tire shop worth their salt will use the proper torque stick on the rattle gun to limit the torque, then will finish with a torque wrench. I set my rattle gun at the lowest setting to just run them up enough to drop the tire to the ground and finish up with a torque wrench. Which torque wrench is best? Unless you are tightening super critical parts like head bolts or aircraft parts, any will do the job and likely be within 10% or less of the correct torque. Much more accurate than the two ugga tuggas method. Difficult to read a beam or digital style while at the hard pull range unless there is an audible when you reach the desired torque, therefore I prefer the click style.

And if you lube the lug bolts, given the same torque, you will stretch the bolt more lubed than not lubed if I recall correctly. But compared to what the shade tree tire shops do with a rattle gun, you are still going to be ok.

And the HF torque adaptor can be used as a relatively accurate benchmark for calibrating your torque wrench, I have seen a few reviews that checked calibration and it is within 2-3%. https://www.harborfreight.com/12-in-drive-digital-torque-adapter-63917.html Good luck reading a beam style to less than 5%.

[Tom M King]

Good torque charts have two sets of measurements. One for dry threads, and one for lubed. The lubed part of the chart usually states it's for 30W oil, so I keep that in a squirt bottle for when I want to lube threads. Always torqued to the chart though.

edited to add one such chart:
http://www.repairengineering.com/bolt-torque-chart.html

[Edward Weber]

That has not been my experience over 20+ years/countless vehicles.

Erik

If you set your torque wrench for say 50lbs on dry threads, the torque will be 50 lbs.
If you do the same with lubed threads you will still read 50lbs but the actual torque on the stud or nut will be higher, since you have reduced the friction in the connection.
This is just a scientific fact, not my personal opinion.

[Greg Funk]

If you set your torque wrench for say 50lbs on dry threads, the torque will be 50 lbs.
If you do the same with lubed threads you will still read 50lbs but the actual torque on the stud or nut will be higher, since you have reduced the friction in the connection.
This is just a scientific fact, not my personal opinion.I think you mean the torque applied to the bolt is identical whether it's lubed or dry but the clamping force will be higher if the bolt is lubed.

[Alex Zeller]

I don't buy into the whole "don't use anti-seize" argument. Often when it's applied the studs and nuts are rusty. Not applying it does just the opposite, under torqueing the nut. The proper thing to do would be to run a tap through the nut and a die on the stud to clean the threads up but most people don't have either. Running the nut on and off the stud wears both down and leaves the dusty rust in the threads which will also impact the torque.

If the threads are in good shape I do nothing. I do put anti-seize on the hub where the alloy wheel come in contact. If the hub rusts it'll make getting the wheel off much harder.

[Bruce Wrenn]

I had a flat tire on the highway and couldn't get the lug nuts off. A cop stopped to check on me and he couldn't budge the lug nuts either. I had to wait for AAA to come with an impact wrench.

MikeThat's why all my vehicles have both a torque wrench and a HF 25 1/2" breaker bar with correctly sized socket for lug nuts. It's amazing how easy lug nuts break loose when using the 25 1/2" breaker bar.

[Adam Grund]

Re-torquing lug nuts after a determined amount of time is nonsense, and often a cover your ass recommendation from shops. If the mating surfaces are clean and no rust or corrosion buildup, and nut/ studs are clean- there’s no reason a properly tightened and torqued nut is going to loosen up after 100, 500, 1k miles.
Wheels are the only thing I’ve ever read the re-torque disclaimer on, I’ve never seen an engine manual that said to torque a head down then drive it 500 miles and re-torque it.
I manually check torque when I need to, or when something just didn’t ‘feel’ right, otherwise it’s an air impact with a torque stick and we’re off to the races. When I have checked the torque stick against a torque wrench, it’s within a few ft. Lbs, which is close enough as far as I’m concerned
But if it gives you peace of mind, it doesn’t hurt anything and there’s value in that.

[John Ziebron]

The posters that talk about a torque stick are correct in that reputable tire shops are supposed to use them. But frequently I think that they may not get used or that "Joe" is using the one that "Sam" needs so Sam just grabs a higher rated one. I don't care about what any manufacturer claims about not using anything on lug studs. If any of you have ever had to change a flat where the studs and nuts have rusted for years you'll know what I mean.

I have been rotating the tires on my vehicles for 55 years and the first time I do the studs get coated with anti-seize. I keep a foldable 4 way lug wrench in my vehicles (you all know how good the manufacturer's lug wrench is) and anytime I get new tires I use whatever means necessary to loosen each lug nut then re-tighten them with my lug wrench (do this one at a time). That way, I know I won't have a problem if I have to change a flat in the middle of nowhere. I have never used a torque wrench for a lug nut (back in the day a mechanic would laugh at you for that) and I have never had a nut or wheel come loose. Be sure to use the opposing tightening sequence though.

[ChrisA Edwards]

Had a round trip from Memphis, TN to Tacoma WA, towing and enclosed trailer. With 5500 miles calculated, took my truck in to my GMC dealership for a service and tire rotation. They also installed my current set of tires (price matched Discount Tires).

I asked them to check my brake pads as I'm still on the original set at 72K miles. They said they were good, but not being 100% confident that they had checked them, I decided to remove the left front and rear wheel to check them myself.

Well, my impact, both pneumatic and air, wouldn't budge the lug nuts. I normally use the electric impact to remove a 180ft/lb nut on the rear axle of my Ducatis, so the truck lug nuts should have spun off easily. My neighbor came down with his 1300ft/lb pneumatic impact and we did get the lug nuts off.

I checked the brake pads and all was good. I used my Snap On (CDI) Torque wrench set the the GMC spec (140ft/lbs I think). After doing that, I tried loosening one just to make sure the 30" breaker bar would work out on the road if necessary.

I will say, I normally use Discount Tire for most of my tire requirements and am one of those guys who watches the whole tire change process ( I had a pneumatic tire changer for changing mine plus friends motorcycle tires for several years), so I like to watch how the 'Pros' do it.

The Discount Tire guys use a torque wrench (at my location) for final tightening.

[Ronald Blue]

As to Johns initial comment I can't remember the last time I have had tires rotated, replaced, or whatever that they didn't use a torque wrench. In fact at Sam's at least a second person verifies the torque and signs off on it as well.

We were always taught to lube everything we were torquing. Even the studs being torqued to 2400 foot pounds. This was with a hydraulic torque wrench or a 16 to 1 multiplier and 1/2" drive torque wrench. If you are installing a head on a John Deere for example the torque procedure is as I recall 3 steps. First 2 were to so many pounds. Then the final was an additional amount of degrees. All with lubricated threads and bolt heads. I have never ran across anything that was supposed to be torqued dry that I recall. So easy for threads or bolt faces to become galled and increase the resistance. The key is that all you do is "stretch" the bolt or stud by torquing it. If the stretch isn't sufficient such as on a head the likelihood of a gasket failure is high.

[Thomas McCurnin]

If you do any offroad stuff, it is recommended that you re-torque those lug nuts every 2,000 miles, but no one I know actually does that.

[Mike Henderson]

I just looked up the recommendations on torque sticks. The recommendation is to use a lower value torque stick and then a calibrated torque wrench to finish.

Mike

[Edwin Santos]

Question from a non-mechanic - do impact wrenches have any kind of clutch mechanism to prevent over tightening?
A few years ago I had my eyes opened to the use of the clutch setting on cordless drill/drivers, and I've now trained myself to always use them when driving fasteners in wood.

[Lee DeRaud]

A few years ago I had my eyes opened to the use of the clutch setting on cordless drill/drivers, and I've now trained myself to always use them when driving fasteners in wood.
The first time I hit the stops on a cordless drill, I thought I'd broken it. :)
(A couple decades back, but still...)

[Tom M King]

My air wrenches have adjustments on them, but there is nothing to go by on the tool other than the knob to turn. My 1/2" Makita 18v impact wrench has more loosening torque than a 1/2" air wrench. It will take lugs off of anything here, from Dually to big tractor. I haven't used a 1/2" air wrench since I bought that Makita.

All the talk about lubed fasteners must have missed my earlier post with the link to the chart. It's fine to lube fasteners, just use the specified torque for a lubed fastener. It's different than for dry threads.

[Edward Weber]

I think you mean the torque applied to the bolt is identical whether it's lubed or dry but the clamping force will be higher if the bolt is lubed.
I guess I didn't word that correctly I hope you know what I was trying to say.

As for those who don't follow manufacturers recommendations, that's up to you. I simply point out that they're there for a reason. 99% of the time you can just tighten down on a lug nut and you'll be okay. That's only because they we designed well in the first place.
Be safe

[Derek Meyer]

I had in incident when I was in college. I took my car (1969 Ford XL, 2 door Galaxy 500 frame) in to have the winter tires swapped for the summer tires. They must not have torqued the nuts down properly, because then next week I was about 50 miles north of town on the highway, at night, and the rear driver's side wheel came off. I heard a *thump* and thought "that can't be good", so I pulled over. I got out and went to get my flashlight out of the trunk, and tripped. Turns out I tripped over the wheel, which was laying next to the car. The nuts had come loose, and the wheel vibrated enough that it reamed all the holes out so much that you could slip it over the nuts and off the hub. It sheared 3 of the 5 studs off completely - they had to be tapped and extracted before they could be replaced. The whell was toast, and I ended up with a used one. The tire place denied any wrongdoing, and since I couldn't prove anything I had to pay for it all. I only had liability insurance at the time, due to the age of the car.

The funny part is, I probably could have driven it on three wheels, as the car's weight was mostly in the front due to the size of the engine. When the wheel came off it got trapped in the wheel well, and I pulled of the road like nothing was wrong.

[Kev Williams]

I read a lightning expert's explanation as to why your rubber tires won't protect you if lightning strikes your car: "A 3 million volt bolt of lightning that's traveled 6 miles isn't going to be put off by 3" of rubber"....

Likewise, I am of the opinion that a nut or machine bolt that is being forced, metal to metal, against the opposing threads of its mating bolt or threaded boss, and an intermediate piece of metal (say, a wheel rim or a crankshaft main bearing cap), isn't going to change the readings of your torque wrench anything close to a significant amount just because there's some oil on the threads. Oil works by filling the space between metal parts with it's bearing-shaped molecules. When you're grinding 2 sets of threads together in order to stretch a bolt, there's no space between the opposing threads for any molecules... If oil on threads did significantly cause the user's torque wrench to under-report the actual torque applied, then there may be a whole lot of cars out there with engines full of over-tightened nuts & bolts...

--and anyway, torque values are not absolute, 'close' is okay. Like tire air pressure; I have 4 tire pressure gauges, all of them 'good' ones, and not a one of them give me the same readings ;)

[Tom M King]

The reason torque on a bolt is important is because there is an optimum range for the metal in the bolt to be stretched to hold what it's designed to hold. Stretch it too much, and the metal will weaken, sometimes even to the point of breaking the bolt, or head off. The stretching of the fastener is the important part, and some assemblies even require the amount of stretch to be measured rather than torque.

Lubricant eases the amount of force required to get to this optimum stretched position. That's why torque charts have specs for dry, or lubed threads, with the lubed torque being lower. If you are lubing threads, and still torqueing them to the dry torqued measurement, they are being over-torqued. Not as important for wheel lugs, but if I'm inside the guts of some machine and want to lube threads, I'll use the torque on the chart for lubed threads.

It's been studied, and proven many times, and ways. https://www.engineeringtoolbox.com/torque-lubrication-effects-d_1693.html

[Jerome Stanek]

A friend of mine fas a torque socket for his 3/4 impact to change tires on his semi

[Rod Sheridan]

“Yes” + apply anti-sieze paste to all threads as well as backs of wheels.

Erik

Erik, most torque values are for clean, dry threads, that’s extremely important, as it guarantees a known frictional value.

Lubricating threads with anti-seize compound results in drastically over tensioned fasteners unless you use a calculated reduced torque value….Regards, Rod

[Brice Rogers]

I think that the people who are rotating tires and tightening lug nuts are at the bottom of the mechanic scale - - probably an entry-level position.

One time I tried to loosen a lug nut after a tire rotation. I was using a 15" star spanner (X-shaped) and the lug nuts were so tight that it twisted the wrench permanently and I still couldn't get it off. I think that I put a torque wrench on it and it wouldn't budge at 200 f.p. So, I took it back to the Big-O (IMHO, that means Big zero) and had them use their impact wrench to loosen it. Then the fun began - - I wanted to do my own torquing of the nuts now that they were broken free. They refused to let me leave the shop unless they retorqued the nuts. I positioned myself between the wheel and the guy with the wrench and told him that I was going to retighten the lug nuts and that they would "have to go through me physically" if they tried to proceed.

Those guys were Neanderthals. They broke a power seat by forcing it and gouged a $200 Corvette aluminum billet wheel (which I made them replace).

Recently I went to a Chevy dealer to get tires rotated. I put paint spots on tires to make sure that they rotated the tires. Guess what ? They didn't. I raised a stink and then they rotated the tires - - except that they didn't follow the rotation order that is in the owner's manual. Is that important? Who knows. But if it isn't, why bother putting it in the manual.

So, I think that the underlying problem is that tires are rotated and nuts tightened by entry-level (probably minimum wage) "mechanics". These folks probably have less knowledge and experience than most on this forum.

[Ole Anderson]

I think that the people who are rotating tires and tightening lug nuts are at the bottom of the mechanic scale - - probably an entry-level position.

So, I think that the underlying problem is that tires are rotated and nuts tightened by entry-level (probably minimum wage) "mechanics". These folks probably have less knowledge and experience than most on this forum.

The issue isn't entry level mechanics, it is entry level management. Mechanics will do what they are trained and expected to do. If management isn't following up and performing any quality control, it is on them. And not just store management, upper level district and national management for the big boys.

[Tom Giles]

After a career as a jet engine technician I always properly the lug nuts. This is especially important for aluminum wheels. And I’ll bet there isn’t a tire tech anywhere the knows how to properly use a torque wrench or actually has a calibrated torque wrench.

[Michael Drew]

Interesting discussion. Seems like a lot of people are saying the same thing, just differently...

For what it's worth, I have a background in mechanics. Millwright, engine builder, rotating machinery (turbines and pumps, etc). I too use a torque wrench on my vehicle lug nuts. I have two sets of wheels / tires for my daily drivers. Winter/summer. I also like to use a light coat of anti-seize, although it really isn't needed with modern wheel studs, as they have a pretty good galvanic coating on them anymore. Unlike pre-2000's vehicles.

It's been mentioned a few times already, and correctly so, that there is an element of friction to consider when applying torque to a fastener. And yes, it does make a difference. A significant amount in most cases, so one should find the appropriate torque values with/without lubricant. And yes, anti-seize is considered a lubricant. Also know that the lubricated values on a torque chart assume that lubricant is between the nut and washer and/or bearing surface in addition to the threads.

Torque values corollate the amount of stretch a stud/bolt will see when the nut is twisted. That stretch is then used to determine clamping force. For example, a turbine case might use 3" diameter studs, it can be impossible to get a socket on them, so we use special nuts that have jacking screws to push the nut up, stretching the stud. We measure stud stretch and use that to determine recommended clamping force. Rod bolts in a typical engine are torqued while using a stretch gauge to get the proper stretch value. GM LS engines use what's called "torque to yield" head studs. You torque them with an angle torque wrench. The stud is torqued to a value xx, then an additional amount of rotation is applied in degree of angle. These are single use studs and are discarded after a single use. Same with GM suspension bolts. They are single use, torque to yield fasteners. GM instructs the use of oil for lubricant as well.

There are pneumatic, hydraulic and battery torque tools that can be set to get the desired torque values, but they are not the typical kind you might see in a garage, and rather expensive. My department uses a few of them for large bore pipe fitting. Here is a link to one of the suppliers we use:
https://hytorc.com/pneumatic
https://hytorc.com/lithium-series-ii

[Edward Weber]

Here is a slightly different perspective on this. Those who are familiar with large truck maintenance are probably aware of this already or should be. If there is ever an issue, it can become a legal issue.

https://www.fleetowner.com/equipment/article/21681200/debunking-a-myth

[Stephen Rosenthal]

I used to do a lot of my own car repairs (pre- computer everything) and never checked the torque. But then I bought a BMW along with the official service manual and noticed that the recommended torque setting was listed for every nut and bolt. Needless to say, I bought a needle beam torque wrench. Got a NIB Made in USA 1/2” Craftsman for $10 at an estate sale. Now I use it all the time. Works great.

[Brian Elfert]

I have a motorhome that takes 500 ft lbs of torque on the lug nuts. Tire shops will use a 1" impact to install the lug nuts and then check them with a torque wrench. A torque wrench isn't going to tell you if they are over tightened! A tire shop flunkie snapped off a brand new wheel stud on my motorhome that I had just installed. Way too much torque was applied.