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Use of Anti Seize on vehicle lug nuts
6

Use of Anti Seize on vehicle lug nuts

Use of Anti Seize on vehicle lug nuts

(OP)
Hi everyone,

I would like to start a discussion on the use of anti seize on vehicle lug nuts. Searching the net, there are people that claim to have used anti seize on lug nuts for many years with no problems, and some people that advise against it.

I have two main questions I would like to address separately. The two questions directly below are related to the two main sources of controversy on the subject.

1. Will the use of anti seize on properly torqued vehicle lug nuts likely cause them to loosen over time, to the point where it could be dangerous ?

2. Will the use of anti seize on vehicle lug nuts cause a significant increase in the axial loads and/or stresses on the lug studs, that would likely cause a significant problem or danger ? If so, I would think you could simply reduce the specified torque by a certain percentage to compensate for the use of the anti seize.  

I have a bottle of NAPA anti seize (item # 765-1674) and interestingly enough, it says right on the bottle to use anti seize on lug nuts.

I would expect most engineers and auto manufacturers to recommend not to use anti seize on lug nuts, even if they're not sure either way whether or not it would cause any problems, just because of safety liability.

On the other hand, one would think that a large company like NAPA also considered safety liability, and would not state right on the product bottle to use anti seize on lug nuts, unless it was a safe practice.

On the bottle of the NAPA anti seize product mentioned above, under directions, it states to apply the product, and then torque all bolts to manufacturers specifications.
The directions make no torque reduction allowance for the lubrication effects of the anti seize, and the effects it may have on increasing axial loads beyond those anticipated at OEM specified torques.

Also on the NAPA anti seize bottle, it recommends the use of the product on engine head bolts, but again, does not provide any recommendation for an OEM torque spec reduction with the use of the anti seize, which leads one to believe that it may not be a significant issue.

Most repair shops are not going to torque your wheels anyway, they will use impact wrenches which always over torque and many times warp rotors. Some shops use torque sticks on the end of the impact wrenches which is a good idea, but you would be hard pressed to find any shop using torque wrenches on lug nuts. It's just not fast enough for them. Even if you request that they use a torque wrench, they may likely forget, so you would have to watch them. I know because years ago I worked in an auto repair shop.

I have used anti seize on the lug nuts of one vehicle I have and I have not had any problems. I used it very sparingly, and I tried my best to make sure that there was no anti seize between the end of the lug nut (part that seats in the rim) and the rim. These were aluminum rims with closed end acorn style lug nuts. I re torqued after driving 50 miles or so which is standard practice on aluminum rims anyway.

The reason I used the anti seize is because I had to remove a tire once and the lugs were so rusted I could not remove the nuts without a breaker bar. I thought they might break. After that, I removed the lugs on all the wheels, replaced them with new lug nuts, and applied a small amount of anti seize to each lug stud at the time of replacement. That was years ago and I have not had any problems.

Many times cars will come into a repair shop with rusted lugs. Some lugs will come off with an impact wrench and others will break off because they are too rusted. However, just because the lug nut came off with an impact does not mean that the stud was not damaged, fractured,  or over stressed when removing the lug nut, due to the corrosion present. This is another reason I can think of to apply something to lug nuts and studs to keep them from rusting.

Is there anyone out there that has had some real world experience with this, perhaps with fleet vehicles ?

I would appreciate any feedback or thoughts.

Thanks
John

RE: Use of Anti Seize on vehicle lug nuts

just consider, if the torque is the same for dry verses well lubricated, the clamping force will be over double.  you then need to consider the ductility of the wheel material.  I measured yield with only a 20% increase in bolt force for alloy

then in the other vain, if the clamping force is maintained the same, then the required torque would be less than half and would result in reduction of the friction preventing the nuts to loosen.

you could safety wire the lugs to prevent backing off if you want to lube

RE: Use of Anti Seize on vehicle lug nuts

(OP)
>byrdj wrote:
"just consider, if the torque is the same for dry verses well lubricated, the clamping force will be over double.  you then need to consider the ductility of the wheel material.  I measured yield with only a 20% increase in bolt force for alloy"

This is worth considering, but we must also consider that if the torque is the same on identical threads, dry and un-lubricated, the clamping force still could probably vary by as much as double. See thread here...

http://www.eng-tips.com/viewthread.cfm?qid=229435&page=1

Of course, when repair shops tighten the lugs down with impact wrenches, they are in many cases going over double the axial loads produced by specified lug torques (I've seen impacts break lug studs right off when tightening).

This would seem to be less of a problem on steel wheels than aluminum, but worth considering in any case.

The thing that puzzles me is, how likely is it that NAPA would state right on their anti seize bottle to "use on lug nuts" unless they did some research and found the practice to be safe ? They also state to tighten all bolts to manufacturers specs after applying the anti seize, making no allowance for a reduction of OEM torque specs.

Safety wire would not seem all that practical. How would it be applied with both open end and closed end acorn style lug nuts ?

John

RE: Use of Anti Seize on vehicle lug nuts

RE: Use of Anti Seize on vehicle lug nuts

2
I've never seen a manufacturer's torque spec for wheel lug nuts in an owners manual.

I suspect that any torque specs found in service manuals are simply looked up from a "standard" table anyway, and have no consideration of any specific joint design.

I have used anti-seize on all of my personnel vehicles since I have had personnel vehicles.  Never had a problem.  Never found a loose nut or bolt when removing wheels.

RE: Use of Anti Seize on vehicle lug nuts

The repair manual for a car that I have on my desk says 150 Nm for the wheelnut torque.

Cheers

Greg Locock

SIG:Please see FAQ731-376: Eng-Tips.com Forum Policies for tips on how to make the best use of Eng-Tips.

RE: Use of Anti Seize on vehicle lug nuts

example
1/2 lug gets 90 ft-lbs dry
from my wallet card 1/2, felpro, 40KPSI loading gets 43 ft-lbs
thus felpro and 90 ft-lbs will have you aproaching stud yield  

RE: Use of Anti Seize on vehicle lug nuts

2
1.  No, using anti-seize will not cause loosening.
2.  Yes, using anti-seize can increase joint preload, perhaps beyond the safe limits for the fasteners and/or clamped components.

You are correct regarding liability.

You give NAPA way too much credit regarding the possible effects of their product on bolted joint performance.  NAPA is essentially a marketing company and isn't involved in engineering.

You are correct that many places will only tighten lug nuts (or bolts, which are used on many vehicles) with an impact wrench.  However, there are many places that do use the torque sticks and a torque wrench.

It is not common practice to retighten wheel fasteners after 50 miles.

The issue of corrosion is an important one.  Wheel fasteners in the past used electroplated zinc coatings that did not provide much corrosion protection.  This would lead to problems such as those you mentioned.  New vehicles use modern multilayer zinc-organic coatings that have much improved corrosion protection in addition to integral lubricant for high preload developed with a "low" torque.  Anti-seize compounds vary widely, some won't improve corrosion performance at all, but do reduce the friction.  It is important to consider friction in the threads and at the fastener/wheel interface and how that will affect the torque-tension relationship.

American, European, Japanese, and Korean automobile manufacturers perform calculation, analysis, and/or testing for wheel fasteners to develop a proper assembly torque, not just a standard value from a chart.   

Regards,

Cory

Please see FAQ731-376: Eng-Tips.com Forum Policies for tips on how to make the best use of Eng-Tips Fora.

RE: Use of Anti Seize on vehicle lug nuts

(OP)
Thanks for your replies.

Corypad wrote:
"It is not common practice to retighten wheel fasteners after 50 miles".

When I worked for Goodyear & we sold a set of aluminum rims, we *always* told the customer and noted on the receipt that they were to return after so many miles to re-torque the lugs. This was never done with steel wheels but always aluminum. If you search the net you will see other people mention this as well.

I don't remember the exact mileage they were supposed to return at, I am pretty sure it was between 50 to 100 miles.

Mintjulep wrote:
"I've never seen a manufacturer's torque spec for wheel lug nuts in an owners manual".

The factory service manuals have both recommended lug torque and a recommended tightening sequence. I had always assumed the factory service manuals were based on engineering data produced by the vehicle manufacturer & not standard tables.

Of course lug torque specs vary from vehicle to vehicle, a pickup will have a higher torque rating than a small car.

Nowadays, more and more shops are using torque sticks for lug nuts which is a good thing. A common problem in the vehicle repair industry whether you get your vehicle repaired at a dealer service department or a general repair shop is that many if not most shops use impact wrenches for things that they should be torquing to specs. For them, it's all about getting things done as fast as possible, not about following service manual repair procedures exactly.

Cory, if the anti seize does increase preload significantly, could the lug torque just be backed off by some reasonable percentage to compensate or would this likely cause other problems ?

Regarding the comment about NAPA being mainly a marketing company, that may be true. Permatex makes the anti seize product sold by napa which I mentioned above. My point is that you would think whoever makes and/or sells the product, would make sure that product packaging would not likely get them into trouble liability wise.

If I were making and selling anti seize, and I stated on the product bottle to use the product on lug nuts, prior to making that statement, I would have conducted test after test after test to make sure that it was completely safe to use on lug nuts. Of course you cannot assume that the testing was done, based on product packaging.

I'm glad to hear the newer vehicles have more rust resistant coatings on the studs and lugs. From a safety standpoint, I believe they should either make both the lug nuts & lug studs out of materials that won't rust (for all practical purposes), or coat them so they don't.

John

RE: Use of Anti Seize on vehicle lug nuts

I got tired of rusted lug nuts decades ago, and have routinely used anti-seize on lug nuts, and on the axle pilot diameters where some wheels take shear loads also.

I use the low end of the recommended torque range with the anti-seize.  That's the torque range recommended by the car manufacturer, traditionally specified with new, clean, oiled studs.  The anti-seize seems to get you close to the same 'feel' with used parts.

I have had shouting matches with tire dealers about _their_ recommended torques, which are generally way too high for alloy wheels.  Yes, I go so far as to bring my own torque wrench to the tire shop, and r/r the wheels from the car myself in their parking lot.

In forty plus years, I have had exactly one lug nut loosen.  Not from the anti-seize; from yield of a brain- damaged design of a wheel cover retainer, made of dead soft steel and too little of it.

 

Mike Halloran
Pembroke Pines, FL, USA

RE: Use of Anti Seize on vehicle lug nuts

I would like to see the car that Mr. Locock has on his desk.

RE: Use of Anti Seize on vehicle lug nuts

John,

No automobile manufacturer recommends retightening wheel fasteners after a short distance.  Perhaps aftermarket shops do.

Yes, the torque could be reduced for joints prepared with anti-seize.

Factory service manuals contain information derived from engineering data.


 

Regards,

Cory

Please see FAQ731-376: Eng-Tips.com Forum Policies for tips on how to make the best use of Eng-Tips Fora.

RE: Use of Anti Seize on vehicle lug nuts

Greg and Cory,

So is the wheel-to-hub connection designed taking into account the huge possible variation in preload that is known to occur in the real world?

RE: Use of Anti Seize on vehicle lug nuts

(OP)
Mike H. Wrote:
"I use the low end of the recommended torque range with the anti-seize.  That's the torque range recommended by the car manufacturer, traditionally specified with new, clean, oiled studs.  The anti-seize seems to get you close to the same 'feel' with used parts".

That's a good point, it would seem important to know whether the original OEM torque specs are for lubed or non lubed threads. If the OEM specs take into account oiled lug studs, I would not expect significant friction reduction when using anti seize.

Based on my own experience and from what I have gathered so far with my research, it would seem better to use a little anti seize on lug nuts as opposed to not using it. My preference is to use it sparingly, an to try to avoid getting it on the seated contact point between the end of the lug and the rim.

I have also heard of people using a little anti seize at the contact point between the back of the rim and the rotor and/or brake drums. Sometimes corrosion can make rims stick here as well although it's generally not as bad as rusted lug studs. I'm not sure whether anti seize here is a good idea or not.  

I have always had good luck with anti seize whenever I have used it. I used to use grease on some threaded connections but found anti seize to be superior.

Just out of curiosity, regarding other applications in general, does the application of grease, oil, anti seize, or lubricants in general on properly tourqued bolted and/or threaded connections, cause any significant contribution to the loosening of the joint ?

Thanks
John

RE: Use of Anti Seize on vehicle lug nuts

I recall reading a camping trailer manual that recommended retorquing every 50 miles for a while.  

The same book also recommended making sure the studs and nuts were _dry_, and tightening until they squeaked... which is a sure way to convert torque into heat, not tension, and ending up with a loose joint, and a fatigued, broken stud.  That's just stupid... well, I wouldn't even call it engineering, just a demonstration of ignorance.

On a related note, when I was a kid, the local service station owner did a good business installing seat belts in cars that didn't come with anchors for them... and went to considerable trouble to punch undersized holes through the floor pan for the anchors, drive the bolts through them with a hammer, and use a big wrench to tighten the nuts on the thread- damaged bolts, on the theory that if it was really hard to tighten, it would be resistant to loosening.  There's an awful lot of ignorance out there...



 

Mike Halloran
Pembroke Pines, FL, USA

RE: Use of Anti Seize on vehicle lug nuts

(OP)
Was it the late sixties Dodge Chargers that used to have left handed lug stud threads on one side of the vehicle and right handed lug studs threads on the other side ? I think it was the drivers side that had the left handed threads.

I think it was an attempt to use the normal forward rotation of the wheels to help to always keep the lug nuts tight. Good or bad idea ?

Perhaps it would mainly only come into play if the wheels were breaking traction and being accelerated and/or spun very fast.
 

    

RE: Use of Anti Seize on vehicle lug nuts

Things haven't progressed much.

Quote:

Elton McBroom Chief Engineer Premier Industrial Corp

There is an impressive pile of ignorance atop the subject of nuts and bolts. This article will spade away the ignorance only if it scares the hell out of you --and you stay scared

Taken from "The Whys of Fasteners Failures": Sports Car Magazine; January 1964.

In 1962 Premier had been invited to Indianapolis Motor Speedway to supervise the tightening of all fasteners. After the race for the first time in history there were no broken bolts laying on the track. They stayed for a couple of years until they weren't needed anymore and the next year  was the year that there a massive failure of external wrenching cap screws. I recall about twenty cars dropped out in the first 6 laps from connecting rod bolt failures.

Whether the reason for the bolt failure was ever discovered I do know that none of the engine builders were told why. All this time I knew and if I had known that this particular fastener was going to be used I could have prevented the bolt related engine failures.  

RE: Use of Anti Seize on vehicle lug nuts

Quote (John2004):

Was it the late sixties Dodge Chargers that used to have left handed lug stud threads on one side of the vehicle and right handed lug studs threads on the other side ? I think it was the drivers side that had the left handed threads.

I think it was an attempt to use the normal forward rotation of the wheels to help to always keep the lug nuts tight. Good or bad idea ?...

I think that this would only make a significant difference if the fastener is actually on the axis of rotation and is there to prevent rotation of the clamped part, as on one end of a double ended Grinder or a crankshaft pulley.

Trevor Clarke. (R & D) Scientific Instruments.Somerset. UK

SW2007x64 SP3.0 Pentium P4 3.6Ghz, 4Gb Ram ATI FireGL V7100 Driver: 8.323.0.0
SW2007x32 SP4.0 Pentium P4 3.6Ghz, 2Gb Ram NVIDIA Quadro FX 500 Driver: 6.14.10.7756
 

RE: Use of Anti Seize on vehicle lug nuts

Mint,

Wheel to hub joints are designed to be robust against multiple tightening methods (hand tool vs. power tool) and conditions (lubricated vs. non).  However, liberal use of anti-seize on newer parts is not part of it, and definitely could lead to damaged parts.

John,

Using anti-seize on the other interfaces is common in Canada and Alaska where corrosion is extreme.  Frequently, those interfaces have uncoated steel parts (hub), so anti-seize can be very helpful.  For new fasteners, corrosion really is much reduced and not as much of a factor.

Using lubricants on threads doesn't contribute to loosening.

As Mr. Clark mentioned, using different thread handedness is only useful if the fastener shares the rotation axis with the joint, and only if the applied forces/torques are of the same magnitude as the preload/resisting forces.  Central wheel fasteners are used in motorsports and exotic vehicles (Porsche, etc.), so the handedness could be switched.  However, the idea of switching the thread instead of increasing preload is not good joint design.

Regards,

Cory

Please see FAQ731-376: Eng-Tips.com Forum Policies for tips on how to make the best use of Eng-Tips Fora.

RE: Use of Anti Seize on vehicle lug nuts

Regardless of any other advice about not using anti-sieze, I've spent way too many hours sitting in my driveway with drills & hammers dealing with the results of broken studs, broken lug bolts(used on Saabs) including the smaller alignment screws to hold the disc to the hub. I won't put the lug nuts back on without anti-seize.

Russell Giuliano
 

RE: Use of Anti Seize on vehicle lug nuts


Gentlemen,

A note from a Survivor...

A few of you have seen me rant and rave about the bizarre black magic voo-doo of trying to achieve a properly-calculated bolt stress by "torquing" a fastener. Well, this thread puts in into context:

Many years ago I almost became a road pizza, a veritable stain on the highway, as a result of this dangerous assumption. As I was heading up to see a client, I had noticed a black mass in the air, growing ominously larger as I realized that it was on a trajectory directly towards me. In spite of turning the wheel slightly and trying to duck behind the dash, this missle from the heavens smashed into the A pillar, raining chunks of glass upon me. Luckily, I was able to maintain control of the vehicle, pull aside (pull myself together) and try to find out what had just happened.

Turns out that I had been struck by an errant wheel whose lug nuts had let go. Why had they let go? Very likely because they hadn't been properly preloaded. Maybe some mechanic simply used an impact gun. Or, maybe equally as useless, he may have used a torque wrench. Perhaps it was even a calibrated torque wrench.

Since torque has dubious or little, at best, relationship to a fastener's residual preload in the real world, it cannot alone be used to control a fastener's "tightness". "Torque" just describes how much resistance there is to turning the nut. There are myriad factors conspiring to add to (or detract from) such resistance. For the most part, many are uncontrolled. Thus, their values, in terms of the K factor, are unknown.

So, whether lube is used or not, unless you measure the final result of the torquing exercise, you're still stabbing in the dark.

Ciao,

HevïGuy
www.heviitech.com

RE: Use of Anti Seize on vehicle lug nuts

(OP)
HeviGuy wrote:
"So, whether lube is used or not, unless you measure the final result of the torquing exercise, you're still stabbing in the dark".

In the case of lug nuts, is there a cost effective efficient way for auto repair shops to measure the final result, bypassing the torque wrench ?

What about the guy who just likes to work on his own vehicle now and then ? I'm assuming anything that measures the final result more accurately than a torque wrench may be expensive.

Cory wrote:
"As Mr. Clark mentioned, using different thread handedness is only useful if the fastener shares the rotation axis with the joint, and only if the applied forces/torques are of the same magnitude as the preload/resisting forces".

I had thought about that, lugs are not like a table saw blade, the shaft the blade is mounted to, turns clockwise, but the nut that holds the blade on, tightens counter-clockwise, & this keeps the nut snug & things more safe.

In the case of the lugs, each lug and stud does not rotate about *their own* common axis but are located radially around a common rotation axis. It still *seemed* there could possibly be a somewhat similar effect, although less pronounced.

Just out of curiosity, why did Dodge design one side of the vehicle with LH lug threads and one side with RH lug threads ? Did they think it would help prevent loosening or were they aiming for something else ?

Cory wrote:
"Wheel to hub joints are designed to be robust against multiple tightening methods (hand tool vs. power tool) and conditions (lubricated vs. non).  However, liberal use of anti-seize on newer parts is not part of it, and definitely could lead to damaged parts".

I would think using anti seize would be very similar to the "lubricated" condition the engineers designed for. As for being designed for power tool use, torque a lug & stud coated with anti seize by hand with a torque wrench, or torque it dry & non-lubricated with an impact that sometimes breaks studs, which one produces more axial load ? I would bet the impact on a dry stud. I have seen impacts break studs off, but I bet nobody has broken a stud with a hand torque wrench and anti seize.

If they're designing for the use of impacts (and they should be becasue many shops use them & in the past almost all shops used them), then it would seem plausible the parts could probably handle the use of anti seize with a hand torque wrench.

In my opinion, unless auto engineers can prove that their new fancy coatings will allow people to never worry about frozen & seized lugs again, in areas where road salt is used & under all practical conditions, then they should be designing for the use of anti seize.  

John

RE: Use of Anti Seize on vehicle lug nuts


Alas, for applications such as this, there really isn't a practical answer (with the exception, perhaps, of colour-changing load indicating fasteners -used simply for their "go, no-go" indicating ability). Industry makes use of technology such as ultrasonics to measure the stretch of fasteners before and after they're tightened. The resultant Delta L provides a definitive indication of the fastener's preload. Plain and simple. No guess work involved or assumptions having to be made. Basic dial indicators have also been used in this manner.

My point was to come out and say: "Hey people, the Emperor is naked!" and get them to really think about the application being fastened, the potential cost of its failure and, hence, the degree of control required to ensure that everything will be fine. Relying on torque alone results in a sometimes dangerous false sense of security

Ciao,

HevïGuy
www.heviitech.com

RE: Use of Anti Seize on vehicle lug nuts

Quote:

Alas, for applications such as this, there really isn't a practical answer

Yeah, we've only been mass-producing cars for 100 years.

And while every once in a while a wheel falls off the hugely overwhelming vast majority of them don't

Apparently the wheel-to-hub connection has evolved to a point where it can tolerate a really big range of preload.  Torque or no torque.  Impact gun or fat guy jumping on a cheater bar or average Jill using the stupid little wrench that comes with the car.  Four out of five, or three out of four.  Cross-threaded, rusted in place, cones the wrong way and all the other things that can and most certainly are done wrong.

And still most wheels don't fall off.

Sometimes good-enough is good enough.

RE: Use of Anti Seize on vehicle lug nuts

How would you use an ultrasonic or dial indicator to indicate lug stretch with acorn-style lug nuts?

RE: Use of Anti Seize on vehicle lug nuts


"How would you use an ultrasonic or dial indicator to indicate lug stretch with acorn-style lug nuts? "

You can't. One needs clear acces to one end of the fastener if measurement is intended.

Sometimes good-enough is good enough.

Until somebody gets hurt. That's when the fecal matter hits the fan and the litigation machine gets fired-up

Ciao,

HevïGuy
www.heviitech.com

RE: Use of Anti Seize on vehicle lug nuts

So, HeviiGuy, should anti-seize be used on lug nuts or not?  What detrimental effect would there be if it is used?

Ted

RE: Use of Anti Seize on vehicle lug nuts

Hello Ted,

There would be no detrimental effect whatsoever if anti-seize (or "bolt snot" as we over here sometimes refer to it as) is used if the residual preload can be verified. This would result in the amount of applied torque being irrelevant to the torque spec: You only apply an amount of torque which will result in the required elongation.

In the absence of being able to verify the load (which in the case of lug nuts would be quite difficult to do), as MintJulep suggests, tell Bubba not to apply all of his weight to the cheater bar sad

Ciao,

HevïGuy
www.heviitech.com

RE: Use of Anti Seize on vehicle lug nuts

(OP)
Mintjulep wrote:
"And while every once in a while a wheel falls off the hugely overwhelming vast majority of them don't"

"Sometimes good-enough is good enough".

In general I agree with both statements, I never had a wheel that I have put on come off, but I worked in a shop where other people had a couple come off. It really is a bad thing to have and see happen. Usually, it's when people get rushed that things start going wrong, but I have seen a few employees that were generally lazy and/or unfocused.

I guess you will always have human error and things will always go wrong, but when you get your vehicle worked on, you want to be able to count on the wheels being installed correctly. There's too much at stake, and being busy or in a hurry is no excuse for not making sure it's done right. That goes for owners, managers, and all employees.

Even if it only saved one life, would it be going too far to implement standards that shops must follow to insure it's done right ? I know that could cause some problems & would still not be fool proof, and then the question of how to enforce it comes up.

I guess all you can really do is try to find a shop you trust or do it yourself.  

John

RE: Use of Anti Seize on vehicle lug nuts

In this part of the world, lots of commercial vehicles have checkpoints fitted.

http://www.cpsafety.com.au/

They don't stop wheelnuts from loosening, but they do make it really obvious to anybody who's looking that something is going wrong long before it causes an accident.

I stopped a van fitted with these last week because I could see from twenty feet away that one of his wheelnuts was working loose.

A.

RE: Use of Anti Seize on vehicle lug nuts


Indeed, I've seen them too. They're a tremendous improvement over the status quo!

Unless I'm missing something, there is, however, a bit of a cavaet with their use as well, isn't there? For example: The concept is that relative movement would alert somebody to the fact that something was gone awry. I would think that achieving the proper bolt stress in the first place, is a key factor. Otherwise, an affected indicator would be showing a "false positive".

Ciao,

HevïGuy
www.heviitech.com

RE: Use of Anti Seize on vehicle lug nuts

My Dodge 1 ton dually actually has a bearing built into the lug nuts. These are supposed to be lubricated at install and then tightened to a given torq value.  I rotate the tires occasionally and do torq the nuts down to the proper value.  They do not come loose..ever.  Infact it takes a 24 in cross to loosen them by hand or a very stout impact tool.  Most 1/2 inchers won't do the job.  I don't think I have ever heard of lug nuts coming loose on any of the 6 truck forums I frequent.

I also have aluminum wheels on my streetrod. These have long studs that protrude thru the lug nuts.  The Lug nuts have washers which I use never-seize on.  Never have problems with them.  The same goes for the top fuel funny cars.  Never had lug nuts come off.  For the most part they are hard to get off once torq to the right value.

RE: Use of Anti Seize on vehicle lug nuts

I have used spray moly anti-sieze on studs and nuts. Instead of using a torque wrench, I judge from the 'creak' at the point of final tightening. Could this spell danger from tire shop torque wrenches? Hasn't occured yet with me.

RE: Use of Anti Seize on vehicle lug nuts

(OP)
Plasgears wrote:
"I have used spray moly anti-sieze on studs and nuts. Instead of using a torque wrench, I judge from the 'creak' at the point of final tightening. Could this spell danger from tire shop torque wrenches? Hasn't occured yet with me".

My main concern would be not so much that anti seize would increase axial load to dangerous levels with the use of a hand torque wrench, but that an impact and the use of anti seize would always create a problem.

As long as you don't forget to make the repair shop torque the lugs to specs, then no problem I guess. Unless someone uses anti seize and does not know that it can change the axial loads, then the guy or gal at the repair shop runs the lug down with an impact. Even if they have a good feel for torque on a dry stud, I tend to think they would probably apply way to much force on the anti seize coated stud. Then you could get broken lug studs, or worse yet, compromised lug studs that seem OK but fail while driving. Not to mention warped rotors.  

Requiring repair shops to always use torque sticks with impacts many not be a bad idea. Torque sticks seem decent, but I tend to think a hand torque wrench on average may be more accurate & consistent. That's just an unfounded suspicion though, I never did a side by side test.

I contacted Permatex & NAPA about this & I will let you know what they say when I get their replies. I suspect they will play it safe and say they no longer state on their anti seize bottles to use it on lug nuts, but perhaps they will surprise me with a real answer.

John

RE: Use of Anti Seize on vehicle lug nuts

(OP)
I found some info regarding wheel stud failure here...

http://www.boltscience.com/pages/failure4.htm
 
The link directly below goes to a page with some interesting information regarding the difference in axial loads obtained when coating only the thread with anti seize, and when coating both the threads and under the bolt head. Apparently, if the information is reliable, there is a huge change in axial load when you coat both the threads and under the head.

http://www.mechanicsupport.com/articleTorqueWrench.html

If you look at the table / charts provided near the bottom of the page, using anti seize on the *thread only* shows slightly less axial load than using no lubricant at all. Is this an error or is there some reason for this ?

The article references another article titled "Failure of bolts in helicopter main rotor drive plate assembly due to improper application of lubricant" by N. Eliaz, G. Gheorghiu, H. Sheinkopf, O. Levi, G. Shemesh, A. Mordecai, H. Artzi, Published in Engineering Failure Analysis #10, pages 443-451, http://www.sciencedirect.com/.

Apparently, it was the anti seize application method that was causing the problems with the rotor.

I wish I could see the full article but science-direct wants $35.00 bucks to see it. I may be able to get it from the Library.

A wheel coming off is one thing, but a Helicopter main drive rotor getting loose or coming off is about as bad as it gets. And to think it happened not because of the use of, but the improper application of anti seize.

You would think that they would certainly have a fool proof bolting system for helicopter main rotor drive plates, that would not depend on the proper application of anti seize.

John

RE: Use of Anti Seize on vehicle lug nuts


You don't need to spend $35 on a report. It's pretty simple: The salient point being made in the article is that one can get a huge  variation in preload with a fixed input torque. Bottom line is: if you don't know what the friction of the assembly is, lube or no lube, your 'chopper main rotor drive plates (and just about everything else) are at risk.

It's not the anti-seize which is at fault, it's the assumption-laden process.
 

Ciao,

HevïGuy
www.heviitech.com

RE: Use of Anti Seize on vehicle lug nuts

Here is the report:
http://www.eng.tau.ac.il/~neliaz/Papers_Files/C27.pdf

Field techs did not follow defined proceedure.  The result was higher bolt tension and bolt failure.  Spraying anti-seize full bolt length reduced (I'm guessing) under-head friction.  Tightening by turning the bolt instead of, as specified, the nut resulted in more torque going into bolt tension rather than being absorbed by bolt head friction.

In these critical joints bolt tension sensing should be used rather than indirect torque monitoring and expecting desired tension.

Ted

RE: Use of Anti Seize on vehicle lug nuts

(OP)
Thanks for the report link Ted.

What about the chart at the link below that shows applying anti seize on the *threads only* actually reduced axial load by a small amount compared to dry unlubricated threads ? Is this an error or is it just due to normal friction variation in threads ?

http://www.mechanicsupport.com/articleTorqueWrench.html

Would it be unreasonable to require engineers to design all *critical* threaded joints & related components (wheel lugs, helicopter rotors, etc. anything where a life may be at stake) to be able to withstand the maximum axial loads produced by torquing lubricated threads to specs with a torque wrench ? The lubricants vary, so they should design for the lube that produces the lowest friction.

It seems anti seize and lube on threaded joints is a good idea in most cases, plus applying the lube produces more consistent and accurate transmission of torque, so it would appear to make sense to always design for a lubricated joint.

I have also read that research has shown that not lubricating the thread and nut face will result in the friction value increasing on re-tightening which subsequently reduces the preload for a given torque value. This would be especially important regarding lug nuts, which are being removed & re-tightened frequently for tire rotations.  

It seems all torque specifications should specify both dry and lubricated threads for reference, & if lubrication or anti seize is required or recommended, it's exact application method should be specified. Although ideally the joint would be designed to withstand a worse case scenario application of lube on both the threads and under the bolt head.

At the http://www.boltscience.com website, they say that it is actually transverse joint movement that causes loosening of threaded fasteners. In the case of a wheel, friction between the wheel and the hub prevent traverse movement. The friction is generated by the axial force generated by the torqued lug nuts.

Because of traverse movement causing joint loosening, it's probably best to not use anti seize or any lube on the back side of the rim where it contacts the rotors, hub, or brake drums.

My feeling is the benefit of using anti seize on lug nuts outweigh any concerns of problems it may cause. I do think it is a good idea to apply the anti seize very sparingly to the lug studs, and to try to not get any anti seize on the contact point between the end of the lug & where it seats in the rim lug recesses.

The last time I used anti seize on lug nuts, I think the way I did it was to smear a small dab of anti seize on the end of the lug stud, then run a lug nut on the stud by hand back and forth until a thin film of anti seize covers most all the stud (almost up to the rim). I ran the nut back and forth on the stud enough times so that it did not push a glob of anti seize between the end of the lug and where the lug seats in the rim when I was ready to finally tighten the lugs down. I wiped off any anti seize at the lug end as required.

The main question that remains is whether to torque the lugs to manufacturers specs or reduce the torque by a percentage to compensate for any increase in axial loads due to the anti seize. My guess is to just torque the lugs to manufacturers specs, especially if you use the anti seize very sparingly and can keep it off the end of the lug nuts where they seat with the rims.

This has worked for me and I think the fact that it did not warp my rotors is a clue that the axial loads are not too outragous. Shops warp rotors all the time with impacts, and they might turn or replace your rotors, but they don't replace the lug studs as a precaution for the possibility of them being overstressed by the impact which warped the rotors.

This reasoning may not apply to all vehicles, especially larger tucks, but for most pickups and cars, I would think that if you have not warped the rotors and you do not feel any break pulsations, then you probably have not overstressed the lug nuts & studs to a point of any real concern.

John

RE: Use of Anti Seize on vehicle lug nuts

I think the difference in tension dry thread vs. lubed thread is small, 5%.  What it does seem to indicate is that thread friction is much less significant than under-head or under nut friction.  Anti-seize on threads only will not significantly change the lug or bolt tension at factory wrench torque.  Anti-seize on the threads and under the bolt head changed the tension to 1.7 times the dry tension.  So anti-seize on the wheel stud and on the lug nut face will significantly change the stud tension.  Without knowing what the expected lug tension is for dry torque, there is no predicting what the fully lubricated tension would be.  Limit applying anti-seize to threads only.

Ted

RE: Use of Anti Seize on vehicle lug nuts

You can go to RS Technologies and get a little more information about applied torque and tension on a fastener. They evidently do a lot of work with lug nuts. The first link is to there fastener testing methods.
The second link is to the download page with several good papers on fasteners. The first paper has a good picture of how the applied torque is used by the fastener. Two can be downloaded and the others have to requested.

http://www.rstechltd.com/fastener_testing.html

http://www.rstechltd.com/Technical_articles.htm

RE: Use of Anti Seize on vehicle lug nuts

The stock steel wheel studs on my '02 Chevy 1/2 ton truck have what appears to be an aluminum coating/plating.  I'm guessing its purpose is to prevent galling or seizing.  The owner's manual specifically says NOT to put any type of lubricant on the wheel studs or lug nuts.  

For the record, the OEM wheels are cast aluminum.  The lug nuts are some steel alloy with zinc plating.  And the lug nuts have never come loose in 90K miles of driving.

RE: Use of Anti Seize on vehicle lug nuts

Ref: John 2004.
I have seen commercial vehicles in England fitted with left and right hand threads. The easiest way to remember the handing is they always tighten toward the front. Ive seen this as far back as the old British Leyland double decker buses. Now granted, these nuts are tightened with an 8' bar and Dolly (With anti seize). As far as persoanal vehilcles, as long as you use a strong arm or decent wheel brace (As opposed to an air wrench) to tighten these nuts, there is no problem using anti-seize.

RE: Use of Anti Seize on vehicle lug nuts

I was always convinced it was the taper on the lug nut that when wedged into the wheel with torque kept the lug nuts from coming loose, not the thread. The thread was there to create the force required.
The left hand thread would only be of benefit for wheels such as the "knock Offs" (one big nut in the middle) on the wire wheels of old Jags. This was stated technically correct earlier I just thought I would give an example.

I've been told that anaerobic thread lock liquids act as a lubricant when in a liquid state, any comment on that? I wouldn't recommend it on wheel studs though, not because it would cause any damage it just isn't necessary.

Yes, I have used anti-seize on wheel studs for 30 years.

RE: Use of Anti Seize on vehicle lug nuts

I seem to remember in the mid-80's reading about some research into the reasons why a lot of British trucks were losing wheels around that then. I was a teenager at the time, but this thread stirred a memory. While looking for a bit more information I found this report from the UK's Transport Research Laboratory might be of interest: http://www.dft.gov.uk/pgr/roads/vehicles/coll_heavyvehiclewheeldetachment/heavyvehiclewheeldetachmentr1727
 
One thing we see on many British trucks these days is a series of indicators which clip on to the wheel nuts and which make any loosening immediately apparent. E.g  http://www.tyre-rite.co.uk/detail.aspx?ID=1402. Are these common in other countries?
  

----------------------------------
  
If we learn from our mistakes I'm getting a great education!
 

RE: Use of Anti Seize on vehicle lug nuts

I think my advisor at the University worked with someone on a MS thesis on the topic. From memory.

First, lug bolts are way over designed for the loads- due to shop, abuse, liability.
2) I think OE's official stance is lug bolts/nuts are to be replaced not reused- then the coating is intact. Torqued dry clean threads.

I personally use a little on the threads. All my cars have bolts or nuts where the head has a conical to seat the wheel. This is where big time friction holds things. I keep it off the seat- just the threads. Replace studs and or nuts when they no-longer thread easily by hand inidcating they have yielded or been cross-threaded.

I would imagine all these combo's are steels with a long elongation. That way they yield and don't break, rust slower, and don't have stress corrosion issues like some higher strengths. They are probably cheaper too.

M

RE: Use of Anti Seize on vehicle lug nuts

IMO, the use of anti seize prevents galling and lubricates the threads. Lubrication using anti-seize may well give only a slight frictional advantage over clean dry rust free hardware, but that advantage opens up widely on used, galled, rusted, or corroded materials. Although torque is no indicator of pre-load, the more friction-free the process of tightening or tensioning is, the greater the chance of achieving a satisfactory pre-load will be.

The use of torque wrenches at tire shops only came into vogue after aluminum wheels became stock equipment on many cars and trucks. Sorry to say, but the torque wrenches aren't for the purpose of accurately pre-loading the lugs. Instead they offer the tire dealer a hedge against fracturing cast aluminum wheels.

Even if lubricated, the larger variable in terms of friction is the tapered shoulder on the lug. This taper design is essentially used to more easily center the wheel on the stud as the lugs get passed over when step tightening. Unfortunately this design also adds a significant surface area resulting in friction read at the torque wrench but not applied as suitable stress.

"Tighten until the stud snaps, then back off half a turn."

 

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