After having a conversation with one of my friends, he suggested when I attach my tires/wheels back on my cars, it should be done at a certain torque force. Over the 57 years of driving, I have owned 18 cars (3 Corvettes), I never torque my lug nuts to a certain force when I reattached the tire/wheel. I just tighten them with an extra push to make sure they are secure. Should the lugs be torqued? And if so at what force and why?

Thanks for your comments.

 

They have a torque spec. 100 ft.lbs. they should be torqued in a star sequence so they are drawn tight, evenly.. the down side of not sequencing or torqueing to spec is the potential to bend a wheel or a rotor. Even a slight bend will ruin a good wheel over time and also cause premature tire wear.
Hope this helps
Bill aka ET

The idea of torque, is to " stretch " the thread of the major pitch diameter of the stud, to the minor pitch diameter of the lug nut, to a predetermined force ( torque spec ) that will not compromise the integrity of stud or the lug nut... too much force will fracture the integrity of the thread., not enough will not add enough stretch and the nut can loosen.

I've been a Hands on automotive engineer for 40 years and a 4th and 5th year engineering co-op teacher in the GM coop engineering program . I torque everything. especially critical with aluminum alloys. GM teaches torque compliance as a requirement... I subscribe to doing it right . I've tested GM techs in the field who think they know it all.. and found that most techs over torque by as much as 30 %..

You can be a world class mechanic and do it right, or you can be a halfassed mechanic and wing it.

 

When you get right down to it, every single nut and bolt on your car has an official torque spec. Most of them don't really matter. When I mount a wheel, I torque it to "grunt" and call it good. If I'm using an impact wrench, I'll set it to like 100.

 

Been a Tech for a big part of my life (Dealership) and never torqued lug nuts. But with really nice Black Wheels, no impact, I hand tighten with long rachet and then torque to 100 foot pounds, and recheck after 200 miles !!!

 

100 foot pounds

 

Since the thread starter ask about "cars" and not just the Corvette I thought I'd post this from Tire Rack. I know not all my vehicles are 100 ft lbs.

Proper installation requires torquing wheel-attaching hardware (lug nuts or bolts) to the recommended specification for the vehicle make, model and year. Torque specifications can be found in the vehicle's owner's manual, shop repair manual, industry reference guides or obtained from the vehicle dealer.

Proper torquing requires using the correct tools, procedures and patterns to prevent over-tightening hardware, stripping threads and stretching studs, as well as will reduce the possibility of warping brake drums, brake rotors or suspension hubs.

Under- or over-tightening wheel-attaching hardware can be damaging and dangerous.

Torque specifications are for dry threads only. The fastener threads should be free of oil, dirt, grit, corrosion, etc. The hardware should turn freely without binding when tightened by hand. It is important NOT to lubricate hardware threads or seats. The friction at which torque is measured against should come from the hardware seats. Lubricating hardware threads and seats alters the friction generated at the lug seat which will result in inaccurate torque readings and/or over-torquing of the hardware.


We recommend starting hardware by hand, snugging them manually and then using a beam or click-type torque wrench to apply the final torque and confirm the recommended torque value has been reached.

We do not recommend using impact guns or torque sticks when installing wheels.

Impact guns deliver torque as torsional impacts, made by internal hammers. Delivering torque as torsional impacts can damage hardware and wheel finish. Some vehicles, such as Porsches, require the use of special sockets to tighten the hardware without damaging their anodized coating.

The proper application of a torque stick requires the use of a lower valve torque stick than the vehicle's specified torque setting first. Only then should the hardware be tightened to the final torque setting using a beam or click-style hand torque wrench. Often this critical step in the procedure is overlooked and the result is inaccurately applied torque on the hardware.

Some of the variables that can cause inaccurate torque delivery:

Type of impact used (air, electric, cordless)
Power (air pressure, air volume, length of hose, size of fittings, battery power, battery age)
Impacts per second
Size of internal hammers
Possible use of additional adapters
Socket size, weight, length
Operator grip strength
Weight of the impact
Applied angle during use
Attempting to fully tighten hardware with impact guns/torque sticks also prevents using a click-type torque wrench to confirm the specified amount of torque is present. While a click-type torque wrench can identify when the selected torque has been reached, it cannot diagnose excessive torque.

Once you have the right tools, use the appropriate crisscross sequence (patterns shown below) for the number of the vehicle's wheel-attaching hardware positions until all have reached their specified torque value.


Tightening and Loosening Patterns

New wheels should be re-torqued after the first 50 to 100 driving miles.

This should be done in case the clamping loads have changed following the initial installation due to the metal compression/elongation or thermal stresses affecting the wheels as they are breaking in, as well as to verify the accuracy of the original installation.

When rechecking torque value, wait for the wheels to cool to ambient temperature (never torque a hot wheel). Loosen and retighten to value, in sequence using the torque procedures listed above.

 

Been changing tires for 45 years. Never torqued a lug nut. Never had any problems, either.

 

Didn't torque them years back when there were steel wheels, drum brakes, and a lug wrench. With alloy wheels and rotors it's a good idea to get out the torque wrench.

 

I agree w/torquing these aluminum wheels. I worked at Goodyear for 5 years when I was younger(MUCH younger-like 45 years ago) and we never knew the word "torque". We'd always grab the air gun and blast away on all the steel wheels that came in the shop-never even thinking twice about it. We just didn't want the wheel to come off after the cust left the shop. I even had a set of Keystones on my 1964-1/2 Mustang that were always put on and taken off with that same gun--but they were chrome plated steel and weighed a ton.
Today's lightweight wheels are made of alloy's that can't take the same abuse those older wheels did and it only takes a few extra minutes of your time to do it correctly. I still take mine off w/an electric hammer drill but I install them by hand tightening, torque to 70 FT LBS in a star pattern and then to 100 FT LBS in the same manner. You'll never have an issue with this type of install.

 

I also check mine after I drive for few miles. Habit I guess. I tighten Corvette lugs by hand.

 

King of overkill here. I always torque mine to 60, then 80, then 100-ft lbs in a star pattern. With a Digital torque wrench does not take me much longer.

 

I see the Old guys saying I've been doing this for 40 years, I am a professional.. These old guys refuse to get with the program as if their age was an issue..Its not their age, its there willingness to be progressive. These guys want to hold on to the past.. I've seen it a thousand times.. Many many Old guys are intimidated with change or technology.. Most tech would never take refresher courses or be certified with new mandatory procedures if it didn't effected their job or to keep it.. Anyone with any thought process would understand that using a specific torque spec is scientifically tested to produce the proper torque, and not be subject to a particular air gun, or air supply or feel as the way to properly tighten lug nuts.

Most Techs that I told to follow GM procedures, where not happy, and when told it could effect their job status they were even more upset, because doing things right meant it would take more time and thus make less money.( one of the reasons GM dealerships and " The Dealership " at Large " get a bad rap. too many prima donnas not enough qualified techs Plus a lot of Tech are unwilling to follow procedures... a very negative employee trait. Noted in their employee jacket. and subject to a build history to terminate.

There is only one way to do something right, and it does not include winging it.. this isn't 1960 , and no one is OLe Dave who has been a mechanic at the Buick dealership for 40 years. The dealership cant wait for Ole Dave to retire.

 

 

I normally buy my tires from 'discount tires' and they will start the lug nuts with low pressure air and tighten the nuts with a hand held torque wrench, and i watch. When in the service as an aircraft mechanic we were always told that there were three ways of doing anything,,,,,,,,,,,the wright way, the wrong way, and the navy way. Only the last way was acceptable ,,,,,,,,,,,,,,,,,

 

Yes and in the navy critical specs where torque and inspected by a safety officer who applied a safety wire to show it was inspected and it was on him if it was not certified and safety wired.
No one " wings it "in the military . Half of my character is bases on military principles learn while serving. I still use those principles today.

Bill aka ET

 

this is one of my pet peeves, i check for the proper torque on all my cars, especially after having new tires installed or getting a free rotation. Ive had wheels that were so tight it took a 5ft pipe on a breaker bar to get a lug nut loose and others that some were finger tight. A good torque wrench and proper tighten sequence every time.

 

I don't understand why anyone wouldn't torque to proper spec. ET and others have provided ample reasoning supporting this.

And for me... the extra time it takes to assure that I'm achieving proper torque spec is minimal. I've never been in that big of hurry where I needed to "skip" that step.

 

Some people do not accept logic and are just too stubborn to say so.. Its the reason why half the people on this forum give bad information , misleading information or alternative facts, and the major reason I always say be careful who you listen too here.

If everyone agrees that torque specs are given in every repair manual offered, and that these specs have been tested and recommended using the most scientific stress to fail test instruments. Will they also agree that anyone who does not use specific torque specs and procedures are just too stubborn, too lazy, or just a self proclaimed Know it all.

I would love to hear the logic of any of these " know it all's " that say torqueing to spec is a bad idea. It reminds me of my Father saying micro wave ovens give you Cancer. Or Computer are just a fad. And if you have a wireless phone you are just a show off. Just a person living on the past, and unwilling to accept, the old ways are " "OLD " and there are better ways, safer ways, more acceptable ways, correct ways.

 

its twenty lug nuts, doing it right takes an extra two minutes.. Its not like you have to meet some sort of a time schedule. too cheap to buy a torque wrench? or Too lazy to use one.
This is the reason why some people have a well maintained and documented car and can command a high price, and other do a half assed job and wonder why their car is not as valued as others.

 

I have always torqued the lug nuts on my cars using a torque wrench to a proper setting. In the case of the Vette, the torque setting is 100 ft lbs as mentioned. Like Choreo above, I do mine in a star pattern, first at 60 ft lbs, then at 80 ft lbs, then at a final setting of 100 ft lbs. It may be a bit of overkill to do it in a three step process, but it works well for me.