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Thread Lock on Bolts

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lysolvolvo

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Joined
Dec 8, 2006
Location
IA
Sooo... I was apparently half-schooled about using loctite or some kind of thread lock chemical on "stressed bolts or fasteners", namely flywheel bolts, and how i shouldn't do that. i have asked several seasoned builders i hang w/ from time to time, check the webs, etc... found little or no relevant information to support this opinion. please enlighten me as to why i shouldn't drop a dabble of loctite on my threads when assembling.
 
Sooo... I was apparently half-schooled about using loctite or some kind of thread lock chemical on "stressed bolts or fasteners", namely flywheel bolts, and how i shouldn't do that. i have asked several seasoned builders i hang w/ from time to time, check the webs, etc... found little or no relevant information to support this opinion. please enlighten me as to why i shouldn't drop a dabble of loctite on my threads when assembling.

Perhaps some casual reading here might be enlightening for you and those seasoned builders.
http://www.arp-bolts.com/Tech/TechInstall.html



Fastener Retention Overview

There are three methods that can be employed to determine how much tension is exerted on a fastener; using a torque wrench, measuring the amount of stretch, and turning the fastener a pre-determined amount (torque angle). Of these methods, use of a stretch gauge is the most accurate.

It is important to note that in order for a fastener to function properly it must be ?stretched? a specific amount. The material?s ability to ?rebound? like a spring is what provides the clamping force. You should know that different materials react differently to these conditions, and ARP engineers have designed each fastener to operate within specific ranges.

On the other hand, if a fastener is over torqued and becomes stretched too much ? you have exceeded the yield strength and it?s ruined. If the fastener is longer than manufactured ? even if it is only .001,˝ it is in a partially failed condition. Therefore, ARP has engineered its fasteners with the ductility to stretch a given amount and rebound for proper clamping.

Heat, primarily in aluminum, is another problem area. Because the thermal expansion rate of aluminum is far greater than that of steel it is possible to stretch a fastener beyond yield as the aluminum expands under heat. An effective way of counteracting material expansion is through producing a more flexible bolt.....
f the stretch method cannot be used in a particular installation, and the fasteners must be installed by torque alone, there are certain factors that should be taken into account. ARP research has verified the following ?rules? pertaining to use of a torque wrench:

1. The friction factor changes from one application to the next. That is, the friction is at its highest value when the fastener is first tightened. Each additional time the fastener is torqued and loosened, this value gets smaller. Eventually the friction levels out and becomes constant for all following repetitions. Therefore, new fasteners should be tightened and loosened through several cycles before applying final torque. The number of times depends on the lubricant. For all situations where ARP lubricants are used, five cycles are required before final torquing.

2. The lubricant used is the main factor in determining friction, and therefore, the torque for a particular installation. Motor oil is a commonly used lubricant because of it?s ready availability. If less friction is desired in order to install the fasteners with less torque, special low friction lubricants are available. With special lubes, the required torque can be reduced as much as 20 to 30 percent. It is important to keep in mind that the reverse is also true. If the torque value has been specified for a particular fastener on the basis of low friction lube, installing the fastener with motor oil will result in insufficient preload; the torque has to be increased to compensate for the extra friction caused by the motor oil.

3. Surface finish is also important. For example, black oxide behaves differently than a polished fastener. It is therefore important to observe the torque recommendations supplied with each fastener."

Maybe look in the catalog cause I don't want to waste more time wandering around their website.
Note that Loctite is not a lubricant, it is a glue essentially.
 
i (we) used a little dab of locktite on the flywheel bolts, as volvo prescribed, fwiw.

check what the official manuals say. oiled, dry or with thread locker. Look back what has been written by ^^ and other engine builders here on the message board. Here is some info.
Once i had an oil pump bolt come loose on my little Honda, since then i am more cautious ofcourse :nod:
 
Sorry, don't need to read the website, more marketing than informative imo, still not getting the point here... sorry for my ignorance or arrogance, whichever. Torquing fasteners is a learned skill, if not art when experimented with. I've always used various chemical lockers and lubricants when assembling equipment (50 gallon paint shakers, automated product storage systems, various high rpm rotating assemblies, cars, etc...) adjusting your torque specs for clean- new surfaces, different assembly and fastener materials, type of stress and force, and non-such is constantly on the mind of an assembler. I have never had a problem with over-torquing or whatnot when using locker or lubricant. Re-torquing when required is accomplished by using a wicking compound on your second reading. every rotating assembly i work with, is finished with a locker, period. from personal experience in past with fasteners backing out in extreme cold, wear, misuse, i've learned to use a locker. using an oxidizing compound vs. an anaerobic is also considered. Oh yea, recalibrating a torque wrench on a reglular basis (after every 10th cycle or after 5 days of non-use) has been practiced for years. I also 'casually read' technical manuals or spec catal.'s at bedtime.
So please waste some more time on me, and explain the reasoning behind not using a locker. thank-you in advance.
 
i (we) used a little dab of locktite on the flywheel bolts, as volvo prescribed, fwiw.

check what the official manuals say. oiled, dry or with thread locker. Look back what has been written by ^^ and other engine builders here on the message board. Here is some info.
Once i had an oil pump bolt come loose on my little Honda, since then i am more cautious ofcourse :nod:

A bolt for an oil pump isn't the sort of fastener under discussion. The critical fasteners that are subjected to heavy cyclical loads is and thats rods, head, mains and to a far lesser degree flywheel bolts.

I use RED 262 of oil pump bolts.

And yes I am aware Volvo and for that matter their cousins over at Saab suggest a dad of some Locitie or similar on flywheel bolts.
There is a thing called INERTIA is procedures and at one time people suggested Loctite on rod bolts too.

Now nobody serious does that.
 
Explain why Circle Track Mag. said to install wheel lug nuts dry, saying that the friction between the lug and nut threads is what kept the wheel on? This seems wrong. I always use WD-40 just to clean the road dirt off and lube them up a little and I know that it eventually evaporates, but it at least leaves a paraffin wax coating to keep out moisture.
 
Sorry, don't need to read the website, more marketing than informative imo, still not getting the point here... sorry for my ignorance or arrogance, whichever. Torquing fasteners is a learned skill, if not art when experimented with. I've always used various chemical lockers and lubricants when assembling equipment (50 gallon paint shakers, automated product storage systems, various high rpm rotating assemblies, cars, etc...) adjusting your torque specs for clean- new surfaces, different assembly and fastener materials, type of stress and force, and non-such is constantly on the mind of an assembler. I have never had a problem with over-torquing or whatnot when using locker or lubricant. Re-torquing when required is accomplished by using a wicking compound on your second reading. every rotating assembly i work with, is finished with a locker, period. from personal experience in past with fasteners backing out in extreme cold, wear, misuse, i've learned to use a locker. using an oxidizing compound vs. an anaerobic is also considered. Oh yea, recalibrating a torque wrench on a reglular basis (after every 10th cycle or after 5 days of non-use) has been practiced for years. I also 'casually read' technical manuals or spec catal.'s at bedtime.
So please waste some more time on me, and explain the reasoning behind not using a locker. thank-you in advance.

Nope, since you characterize it as wasting time, obviously you know way better that a company who expends enormous effort studying the whole subject of high performance fasteners, and work with the whole worlds really serious engine designers and builders.

If fact, I suggest you to contact them and apply for a job as a fastener engineer/designer.
 
Explain why Circle Track Mag. said to install wheel lug nuts dry, saying that the friction between the lug and nut threads is what kept the wheel on? This seems wrong. I always use WD-40 just to clean the road dirt off and lube them up a little and I know that it eventually evaporates, but it at least leaves a paraffin wax coating to keep out moisture.

They're wrong.
I do have a freind doing the same rally crap that I do or did in both our cases who has insane ideas of assembling stuff dry becuase "If you have grease all over everywhere then it picks up dirt all over".
Typical exaggerating to an extreme. Nobody said "Neverseeze" "all over everywhere".
I use a little smear on the threads of chassi fasteners and under the bolt head so we know its not binding and galling we feel but tightness.

Fawk me is it really that hard to finger out?
 
Most engine fasteners which are properly torqued shouldn't need loctite to stay tight. The loads in an engine tend to be high, and of a repetitive nature. If the loads are high enough to overcome the fasteners clamping load frequently (like in a rod bolt getting cyclically loaded 100 times/second), they WILL loosen or break loctite or not. Consequently the designers spec the fasteners to be able to take the punishment the application requires (or so we like to think). These fasteners are almost always spec'ed for lightly oiled installation (oiled fasteners require less torque for the same preload, and will give a more accurate preload). I think loctite is specified for chassis fasteners since they can invariably see some ridiculous loads over their "spec" on an occasional basis (potholes, Massachusetts roads, idiots catching air in their vehicles etc). Without the loctite these types of occasional loads would make them start to loosen and eventually you'd start dropping suspension pieces. Anyways, there is a large body of knowledge behind designing bolted joints... and books/research papers/etc are all available for the reading if you want to know more. Carroll Smith's "Nuts, Bolts, Fasteners and Plumbing Handbook" is a good starter.
That being said, according to Carol (who isn't gospel but most of his rec's are reasonable), you should always use RED loctite on flywheel bolts for race apps. Of course RED loctite is "permanent" so is supposed to be removed with heat. (ie a torch) I think he said something about "racers drive faster when they know their legs aren't going to be sheared off by the flywheel". I was thinking something similar when I put loctite on my brand new flywheel bolts...

James
 
Nope, since you characterize it as wasting time, obviously you know way better that a company who expends enormous effort studying the whole subject of high performance fasteners, and work with the whole worlds really serious engine designers and builders.

If fact, I suggest you to contact them and apply for a job as a fastener engineer/designer.

You are such a troll! Good grief! You copy paste from APR a bunch of stuff that translates to "different situations equal different torque specs." Nothing in the crap copy paste job you pullled there stated "don't use loctite". All it said was that different situations equal different torque specs. And what was listed as causes of this is so wide and far, it makes you wonder what the point of knowing the torque spec is? Why not do what is recomended and common practice by almost every professional wrencher, wrench to seat, torque to meet.(In other words, wrench until the bolts are seated, then use the torque wrench to make sure they are all equal so one bolt isn't taking more stress than the rest)

Loctite isn't meant to seat the bolt, it is meant to help keep it seated no matter how much stress and vibration is put on it. It seems lysolvolvo isn't disagreeing with APR, actually he is agreeing with APR, saying it is wise to use a seating compound(ie loctite). You forgot to copy paste that from the APR website, but all well, guess the info APR puts out is only right when it doesn't fly in the face of your ignorance.
 
Nope, since you characterize it as wasting time, obviously you know way better that a company who expends enormous effort studying the whole subject of high performance fasteners, and work with the whole worlds really serious engine designers and builders.

If fact, I suggest you to contact them and apply for a job as a fastener engineer/designer.


Thanks so much for your insight and help... I was asking only about flywheel bolts in specifics, and since you still can't seem to answer my question, I feel I was the one waisting time. I was also referring to YOUR comment characterizing the waste of your time answering MY question. And since this issue has gone on for several weeks, I promise I will no longer waste my time on this.

Like I stated at post, I can find little relevant information supporting the opinion of not using a locker on flywheel bolts. Much more has been said, imo, to support the practice of USING a locker on flywheel bolts. Implementing a broad set of rules and guidelines to very specific subjects may be more dangerous than stupid, meaning a difference exists between flywheel fasteners and rod bolts.

I submitted this question because I had never heard of the non-use practice on flywheels, until recently, and wanted some input from TBers to help resolve the questioning of my own personal best-practices. Thank you all who responded and changed my mind on serious inquiry into the subject matter. toodles.

woah, a newbie from iowa, cool.

Carroll Smith's "Nuts, Bolts, Fasteners and Plumbing Handbook" is a good starter.
That being said, according to Carol (who isn't gospel but most of his rec's are reasonable), you should always use RED loctite on flywheel bolts for race apps. Of course RED loctite is "permanent" so is supposed to be removed with heat. (ie a torch) I think he said something about "racers drive faster when they know their legs aren't going to be sheared off by the flywheel". I was thinking something similar when I put loctite on my brand new flywheel bolts...

James

Thanks for the info on the book, will check it out. Thought the same thing too.
 
Last edited:
(50 gallon paint shakers
BIG blink. I would use threadlocker on that rig, too.

I use RED 262 of oil pump bolts.

And yes I am aware Volvo and for that matter their cousins over at Saab suggest a dad of some Locitie or similar on flywheel bolts.
There is a thing called INERTIA is procedures and at one time people suggested Loctite on rod bolts too.

Now nobody serious does that.
Me too. And yes, I can remember loctite on rod bolts, before I learned better.

Car Bomb, you need to check yourself. The best shop managers in the world force their mechanics to read the manual, even to the point of taking the books home. Yes, I used to take the books home. It's a lost art, self-education.

Explain why Circle Track Mag. said to install wheel lug nuts dry, saying that the friction between the lug and nut threads is what kept the wheel on? This seems wrong. I always use WD-40 just to clean the road dirt off and lube them up a little and I know that it eventually evaporates, but it at least leaves a paraffin wax coating to keep out moisture.
Tire Industry of America says the same thing, and they are wrong, too. They know tires, but not fasteners.
I use anti-seize on lug nuts and anything that doesn't shake loose, but might corrode.
I use loctite on brackets. I use grey bolt prep sometimes, and many of the other magical compounds that Permatex and Felpro make.
 
Flywheel Bolts! I had a B20 flywheel escape on me one time and I know of several other racers who have had the same thing happen. So, I'm kinda fussy about how I bolt on the flywheel. This is what I do and I would welcome suggestion on how to do it better.

First I make sure the metal around the bolt holes on the crank is flat by drwawing a flat file across them. Then I clean the mating surface of the crank and flywheel super good with brake clean. I clean the threads with tap and break clean. Clean the bolts too. I apply a little red locktite and torque to 55# plus. I use upgraded fasteners like arp.

Loctite is a poor lubricant so more tightening torque is needed to achieve adequate clamping force. The bolts are so short that there is very little stretch. If you get into any detonation there is probably some movement between the flywheel and crankshaft so the locktite may help hold the bolts is place if this happens. Haven't had the flywheel come loose in the last 10 years of racing so I'm reluctant to change this formula.
 
Flywheel Bolts! I had a B20 flywheel escape on me one time and I know of several other racers who have had the same thing happen. So, I'm kinda fussy about how I bolt on the flywheel. This is what I do and I would welcome suggestion on how to do it better.

First I make sure the metal around the bolt holes on the crank is flat by drwawing a flat file across them. Then I clean the mating surface of the crank and flywheel super good with brake clean. I clean the threads with tap and break clean. Clean the bolts too. I apply a little red locktite and torque to 55# plus. I use upgraded fasteners like arp.

Loctite is a poor lubricant so more tightening torque is needed to achieve adequate clamping force. The bolts are so short that there is very little stretch. If you get into any detonation there is probably some movement between the flywheel and crankshaft so the locktite may help hold the bolts is place if this happens. Haven't had the flywheel come loose in the last 10 years of racing so I'm reluctant to change this formula.

according thier Worldwide Designers Handbook, yes and no, for steel on steel, lower K value than oil lubricant, for aluminum, much higher K value. As for the book, for having over 450 pages, threadlocking is less than 30 pages or so.....

as for myself, I like to use what the factory(s) decided on when to use and not use a threadlocking compound...
 
Car Bomb, you need to check yourself. The best shop managers in the world force their mechanics to read the manual, even to the point of taking the books home. Yes, I used to take the books home. It's a lost art, self-education.

I think reading comprehension might be a lost art on you. My gripe was the fact he ignored all the information put forth by ARP, let alone Loctite. I actually read their entire site, as well I read Loctites. Beyond that, I have at least 20 books on automotive issues, including multiple engine building guides. All of these publications with relevant information strongly recomend the use of a thread locking compound on flywheel bolts, especially in high performance applications.

It seems you are assuming there is just one type or form of Loctite, this is not true. Try practicing that lost art form of self education. There are Loctite formulas for constant stress situations, like a fly wheel bolt.
 
I think reading comprehension might be a lost art on you. My gripe was the fact he ignored all the information put forth by ARP, let alone Loctite. I actually read their entire site, as well I read Loctites. Beyond that, I have at least 20 books on automotive issues, including multiple engine building guides. All of these publications with relevant information strongly recomend the use of a thread locking compound on flywheel bolts, especially in high performance applications.

It seems you are assuming there is just one type or form of Loctite, this is not true. Try practicing that lost art form of self education. There are Loctite formulas for constant stress situations, like a fly wheel bolt.


noob....JohnV and MikeP have probebly built more engines than books you have read....rookies they are not !!!!
 
I think reading comprehension might be a lost art on you. My gripe was the fact he ignored all the information put forth by ARP, let alone Loctite. I actually read their entire site, as well I read Loctites. Beyond that, I have at least 20 books on automotive issues, including multiple engine building guides. All of these publications with relevant information strongly recomend the use of a thread locking compound on flywheel bolts, especially in high performance applications.

It seems you are assuming there is just one type or form of Loctite, this is not true. Try practicing that lost art form of self education. There are Loctite formulas for constant stress situations, like a fly wheel bolt.

Jeeezuz for a guy who signed up maybe 2 weeks ago you sure seem to be full of yourself.

Glad to see you have at least 20 books.
What do you do for a living?
How many high performance engines have you built in the last 2 years?
Last 10 years?
20? 40?
Tell us about yourself. You seem to have tons of self confidence, and it must be based on something.

I'm always ready to learn but I need to know a bit about who is doing the teaching.

Give you a hint whoever you are, most people in the car repair and rebuild business, most especially in those areas where pushrod V8s are the dominant market, do things mostly based on received dogma.

If you don't understand the role of received dogma in what people say and do then I'm afraid there's little point in arguing---which frankly seems to be what you are interested in doing.

Rather ironic that you call me a troll, when you come as a total newb and begin by insulting people.
 
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