Importance of torque specs

Hi all, I am new here and have a question about torque specs. When DIY brake pads and rotors and spark plugs etc.. there are torque-ing specs that many owners are very **** about complying to factory specifications. Might be a stupid question, but how important are they? I know this isn't your chevy or ford that you just want the plugs "snug" and the caliper holding mounts snug, but why are the torque specs so important? Would putting the bolts, plugs, etc.. back after the job without abiding by the torque specs (simply making sure they are snug) cause any problems? Any and all input would be highly appreciated. Thanks!

I'm no expert here, but I assume you did a brake job and are nervous you did something wrong. One of the main reasons behind torque specs is because your definition of snug is different than mine. All bolts are not created the same and you are screwing into different types of metal. I'm not saying I'm perfect as I just torqued a bolt off an exhaust clamp last week with my version of snug. Too much and you run the risk of breaking bolts, too little and the bolt could loosen or leak in the case of the spark plug and lose compression. Just spend $80-100 bucks and get a nice 3/8" drive torque wrench. No reason this shouldn't be part of your kit.

I've done over 90% of my repairs to date without using a torque wrench. I think the rest of the world is with me. You'd be fine. There are some sensitive items such as head bolts, engine component fasteners, etc., but for the majority of the car's fasteners, using good judgment (and not over tightening) works just fine. Flame on!

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Thanks! Im planning a DIY brake job and spark plugs. I've never used a torque wrench on any of my other cars and I was just curious as to why a lot of Porsche guys are **** on torque specs. Never thought or learned of the importance of torquing so I thought I'd ask. Much appreciated!

so ford and chevy bolts just get snugged ???? dude....PUT THE WRENCH DOWN AND STEP AWAY FROM THE VEHICLE before you hurt yourself

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Not yet, but Im planning to do all 4 brakes and changing the spark plugs. Ive never torqued much on any of my other cars so I was wondering why a lot of Porsche owners are **** about torquing. Thanks for the info!

Paul is right for somebody very familiar with wrenching on cars for a long time. For me I started at age 15 building hot rod Chevys including swapping motors and transmissions and building up motors etc. And then building race cars and eventually getting into maintaining high end German cars such as BMW Audi and now porsche. So more than 30 years under my belt. So I know what the right torque for a given fastener should be without looking up the specs. But I do use one for larger bolts that need 60ft lbs or more like suspension and wheels and some motor items. But for somebody just starting out this would be useful and a good practice until you really start to get a feel for it.

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Thanks, That's why I thought i'd post this. I worked as an apprentice at a local auto shop and my mentor never got into detail about the importance of torquing. Seeing most Porsche guys stressing the importance concerned me a bit, granted I know the build quality on these cars are unique, I figured i'd ask. I don't think it would make a catastrophic difference as I never torqued anything on my A5 which never gave me any problems (the only other german car I own). I did brakes again and there were no problems pertaining to my last brake job. I guess it's just experience and the "gut" feeling of when you know something is too tight or too loose. Much appreciated.

I think we can all agree torquing head studs is a different story than torquing brake components. Like I said, I'm guilty of not torquing all the time. I've wrenched on cars for years, but none of them as fine a machine as my P-car. Every turn of a wrench on this car is spiritual. Hence why I torque religiously.

Torque wrench is very important. Some small fasteners do not need much and you can stretch or strip one out. or not get enough and it will back out.. Wheels ALWAYS GET TORQUED. Head studs now a days are torque to yield go to 30 ft/lbs and then 180 degrees more or some such value. Brakes are pretty important to get tight enough as is most suspension bits. Screws that hold visor or door panels? not so much.

Using a torque on hardware for brakes, wheels, halfshafts, heads, internal motor parts, suspension parts and I'm sure a half dozen others are pretty important. Torques for hardware such as airbox hardware, secondary fan, muffler cans, bumpers, tail lights and the like can get away with 1/4 turn past snug. Why trust your "feel" when you can have a calibrated instrument be sure? Torque wrenches are not that expensive.

Torque wrench?? You don't need no stinkin torque wrench! Just crank it down till it strips then back it out 1/4 turn.

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There we go! That's what I was looking to hear from someone, and here we have it. Good man.

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It's not about torque wrenches being expensive. I've got a fully stocked snap-on tool box I love to death. Sure, there are parts that need to be torqued such as internal motor parts etc.. But why all the religiousness for torquing everything like plugs and what not? I do everything myself to my Ferrari 308 and never have I torqued anything on that nor heard of anyone torquing on components of the 308. Never had any issues. When I began working at my auto shop as a youth my boss taught me to use the star pattern when putting wheels back on...we had a set of torques for wheels but seldom used them. Go ahead and call him names but that worked and we were the most successful shop in the area.

"I do everything myself to my Ferrari 308 and never have I torqued anything on that nor heard of anyone torquing on components of the 308. Never had any issues." Every Manufacturer has and uses torque spec's. Have you ever cracked a service manual? If so, I'm sure you'd have seen torque spec's - in other words, they're not exclusive to the Porsche brand... Use them or not, that's up to. FWIW I'd be highly skeptical of any "mechanic" who either (A) Didn't consult said manual for any important torque spec. (i.e. - engine components especially internals, suspension/steering components or brakes) (B) Doesn't know why Torque spec's are important Obviously, it's your car, do to it as you will, but I wouldn't let you anywhere near mine

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Funny. Internal engine parts need to be torqued properly but unnecessary things like spark plugs do not. A home mechanic that thinks he can do just as good a job without using a torque wrench as someone who uses a torque wrench is the very definition of a shade tree mechanic. My advice, and this was impressed upon me by my auto mechanic buddies years ago, is to always use a torque wrench. I have followed this advice not only for my Porsches, but for all other cars I have owned since the very first one. I have 3 torque wrenches, a 1/4" drive inch/pound wrench, a 3/8" drive foot/pound wrench, and a 1/2" drive foot/pound wrench and use them whenever a fastener has a torque call out. My goal is to complete the job and do the job right and only do it once. It is not to see how sloppy I can work and what I can get away with.

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That is the difference between Italians and Germans......"hey Antony tro da nuts on dat wheel with a little love from momma Corleone" or "you vill torque the 12mm nut to 17.25 lbs or else!......veee have our vays...."

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Nein! 23,39 Newton metres

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Holy Crap! I'm not even going near that one... P.I. to the max! You're clearly not aspiring to a career in politics. How insensitive of you...

Anything safety-related gets torqued, along with anything that would cost a lot to fix if it got stripped due to hamhanding on my part. It's not like torquing takes that much extra time...I keep one torque wrench exclusively for torquing lug bolts / lug nuts so I NEVER have an excuse to "good enough" a wheel. When getting ready for a hard drive or an AX or other event, five solid "clicks" on each wheel is reassuring...

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What periodicity do you have your torque wrenches calibrated? Or should I say have you ever have had them calibrated? I'm sure us shade tree mechanics always get them calibrated on a 6 month periodicity.....

Of course, the Porsche mechanics, if a torque wrench is NOT available, have been known to torque all bolts to a precise single value: "Guttenfookentite."

I have two, one in in-lbs and one in ft-lbs and use them wherever there is a spec for it. Don't know why you wouldn't. Things like oil pan cover, or lug nuts, even if you don't have the spec, wouldn't you wanna know that those 10-15 bolts that go in a circle are all torqued down to the same torque value. Lug nuts especially, watched it many times when a guy is jumping on breaker bar tightening the lug nut on the wheels cause tighter is safer. Next thing you know you are chasing one of your wheels down the road, discs are getting warped... So basically using torque wrenches i like to avoid two things, over-torquing and inconsistent torque values on parts that require them to be the same.

I have a deflecting beam Craftsman 1/2" torque wrench. No calibration needed. just make sure it starts on zero. Cheap click type are never close even after a calibration. Snap on and other high end will keep close to spec as long as bubba doesn't use it as a breaker bar.

I always use a Torque wrench... where needed. Last year, I got it checked at a friend's shop and it turned out to be close to accurate (1% off is what he said).

If you are interested in this subject, I recommend a visit to ARP - their website. This world has changed a lot. No more engine oil on threads - Use ARP assembly grease , no more torquing to full value in one shot - sequential/progressive, angle gauges, scrupulously clean thread, chased thread holes , at least 5 different thread lockers/sealers. I am rebuilding an M96 now with as much ARP as I could find. It is astonishing to see the upgrades on ARP fasteners compared to OEM-Porsche -yet very little extra cost. If you do worry about stripping a threaded hole, do not forget the s/s stud+loctite alternative.

for general DIY stuff, the Harbor Freight torque wrenches are fine. They always have them on sale for $10-$12 each and lifetime warranty. Just do a search for their coupons Before the anti-HF flaming begins, would I rebuild an engine with them, probably not. For lug nuts, oil changes, and most DIY stuff they are fine. BTW, I had my $10 1/2 HF torque wrench checked against my indy's $400 German one that had just been calibrated and I was within 2%

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IIRC the calibration was due after 5000 uses. In my automotive work I never came close to using one that much. And as my auto mechanic buddies advised, I treated the torque wrenches like the precision tools they are and didn't throw them about, let them rattle about in a draw filled with other wrenches, always put the wrench back in its case, etc. Bur sure, were I to resume on this I'd have them checked/calibrated.

In my experience, where noted torque values are available, they are extremely important. For me, it's careless to ignore them.

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Just FYI, my Ford F150 EcoBoost has a plug torque of 11 ft-lbs... Not really more than snug plus a very light tug. I've seen plenty of damage done by 'torque wrench rookies' pulling on a light bolt with a 18" torque wrench, not noticing the 'click', but then hearing the 'snap' as they break the bolt clean off. :-(

Please ignore Ex-Tanker. His posts are usually sadly wrong,sarcastic or just plain nasty and ignorant.Really he should be ex-Rennlist ! He is the guy who advizes Rennlisters they can insert M96 4-5-6 piston circlips without the Baum tool ! Back to Torque Wrenches. The problem with the smaller ones we use on the M96 is the 'click' is very feint and difficult to feel. I was reluctant to invest in one of the new designs until I considered the cost/aggravation of timsert/helicoiling in an awkward location ! http://www.brownlinemetalworks.com/torque-wrench I still use a big, clunky BRITOOL torque wrench that makes a very loud click that reverberates through the handle -great! But now we need angle gauges also - I use Brownline.Yes it beeps and flashes! http://www.brownlinemetalworks.com/d...acklit-display Comments about what people do with steel/steel situations are irrelevant to our steel/aluminum alloy situations. Hope this helps but I am not an expert in this subject -just a user.

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That's not bad, $150 for a quality digital torque wrench A lot better than $500 for a Snap-on

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Bit of a rant. Apologies. I can't personally speak for mechanics, but as a scientist/engineer I encounter two types of those, and I think it translates to other areas of life. 'professionals' who have gone through the motions, know some things, and been able to convince people to pay them before they clock out for the day, and 'Professionals' who take pride in their work, know why they do what they do, and are always striving to be better. I've encountered too many lower-case professionals doing good-enough work, which often results in the real Professionals getting called in to fix it. Upper-case Professionals are worth their weight in gold when you can find them. Regarding mechanics, I have quite the collection of broken/stripped lug bolts, and re-repairs for my other cars, that I'm tired of 'professional' mechanics. I as a humble DIY'er, who actually cares, I can do better than that, and will use a torque wrench. I'm still looking for a Porsche Professional in my area if I need one. Edit: I'm also just grumpy today.

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Anytime you are installing a part into aluminum threads you want to torque the fasteners to minimize stripping the threads or not have enough torque to lock the part in place

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I agree with the sentiment, but not the conclusion... I've seen far more snapped bolts from improper use of a torque wrench then a decent mechanic would snap doing torque by feel. The right tool (or what a diy mechanic thinks is the right tool) in the wrong hands in no way means the job will be done correctly, and I think torque wrenches are perhaps the #1 tool that causes "Oh-S##t!" moments? But i also said that five years ago when this thread originated before it was necro-bumped.

All people who 'poo poo' torque wrenches clearly have not studied fastener design, intended bolt stretch, and clamping pressures, let alone what the material either part is made from. I have a KTM bike where 5Nm (3.7 Ftlbs) is commonplace and 'just snug on the handometer' can be the start of a thread strip.

I'm fairly new to working on a Porsche, but I done a lot of work on a lot of things. Application is everything. I always use torque wrenches for engine internals and lug nuts. (As an attorney, I saw a NASTY "wheel off" case. But for years I never torqued lug nuts and never had a problem.) Equally significant are carbon fiber bicycle parts. A sudden failure of a carbon steerer tube or handlebar is decently likely to result in a very different looking smile in the best case. I also usually use torque wrenches on small bolts for gaskets like valve covers and oil pans--like on old American cars where the part is stamped and if you over torque it, it will leak forever. I have a hard time feeling the torque on small bolts. Spark plugs ... you should have a feel for the crush washers. But some are extra touchy, like on Ford 4.6 mod motors, where there are like two threads and if you goof them up, you're in a world of hurt. Something to keep in mind on parts like brakes and suspension--is there any corrosion in the hole or on the bolt? Did you clean the bolt on a wire wheel and clean the threads with a tap? I usually don't. And if the threads aren't as clean and pristine as new, the factory torque spec doesn't mean much. I almost never use a torque wrench for brakes and suspension. Is the bolt a bit stretched? I've reused lots of bolts I shouldn't have, and there is no point in torqueing then. And even some of the most critical things--I'm thinking of the SMALL cap screws that hold the front driveshaft on on some older Jeeps--sure, the wrong torque and you can die--but no way you are getting a torque wrench positioned for an accurate reading. You try to judge based on whether the box wrench you grabbed is a long one or a medium length. A lot of it is knowing by feel when the bolt is not tight enough to hold and knowing when it is about to go over torque and start to stretch, and ultimately, break. I suppose you learn that by breaking a lot of bolts and stripping a lot of aluminum holes. Which I hopefully got out my system decades before I owned even a cheap Porsche. So, yeah, I own a lot of torque wrenches, beam and click type, from very small to pretty large. (I echo that the Harbor Freight cheapie is pretty good). And I mostly don't use them. Heck, sometimes I just ram it on with the rattle gun and call it a day. But it isn't like using them is ever a bad idea. Paul

Human nature is to overtighten and break. �more is better�. Torque specs takes the guess work out and later worry.

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Dammit. You said it before I got the chance to.

How long did you need in order to have the chance? He beat you by 5.5 years!

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I think you might have missed my point entirely, as those are *exactly* the kind of fasteners that will be stripped/snapped when someone thinks they are doing the right thing and uses too large of a torque wrench to try and torque to 5Nm! If anything, a torque screwdriver is appropriate for a super low torque bolt, but NEVER a larger torque wrench, even if is within the very bottom of the scale...

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You must have been pretty grumpy to dig up an almost 6 year old thread and throw a rant on it... I hope you're feeling a little better today... carry on

I do feel bad about that. I don't even know how I found this one to begin with! But yes I'm feeling much better now.

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LOL! I didn't even notice the dates! I thought this was a new thread.

My .02cents, torque wrench accuracy is +- 25%, torque+angle is +-15% accurate, bolt stretch is +-3%-5% accurate. These methods show the accuracy of obtaining the correct " clamp load" of a typical fastener. A seasoned professional with decades of muscle memory twisting bolts can easily get closer than +- 25% by hand.( example/ torque spec 100ft/lbs,=10,000 lbs clamp load, torque wrench accuracy 75 ft/lbs -125 ft/lbs = 7,500lbs-12,500lbs clamp load ). The inaccuracy is not in the torque wrench( they are very accurate ), but in the threads/heads friction of the bolts/holes....K-.015...,K-.018,....K-.020...( with a good "feel" a Pro can tell if the friction is higher or lower than perfect).. A Novice should never rely on muscle memory , and very light torque values under 10 ft/lbs and especially under 12in/lbs the correct tool is needed, you can break a bolt by sneezing while torquing. This is why the torque+angle method is much more accurate than the "torque only " method. It takes out most friction by using a low torque value, then uses angle/thread pitch correlation for clamp load/stretch as is much more accurate at getting very close to ideal clamp load.

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Hello friend Although I have a 997 but my question is also relevant here and I would love to hear your opinion as well in order to be 100% relaxed. I accidentally reinforced my spark plugs with a 40-42NM "so-called" tightening instead of 30-32NM. The reason I am writing "so-called" is because I used a cheap torque wrench that includes a huge range of 28-210NM When the torque I need is right at the bottom and bottom line of the torque wrench. In addition, This torque wrench has also been lying around in my warehouse for a few years (it sure is not calibrated). I made a mistake of children .. (I was confused in reading the numbers on the torque wrench- images attached) Anyway, Sounded "click" while tightening and it did not feel to my mechanic over-tightening and everything closes well and works well. I'd be glad to hear your opinion. Do you think I have anything to fear? Is there any point in disassembling the plugs and replacing them with new ones? Do travel like this for a year / 10-20 KM then change. I want to be 100% calm so I ask you too Thanks!

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That's over-torqued by quite a lot. For piece of mind and to be 100% correct i would. 1. Replace spark plugs, 2. Check for thread damage. (1) over-torquing can damage the shell of the plug and also the threads. It will also cause the plug to overheat. (2) screw a new plug in by hand almost all the way , but not seated. It should screw in easily but not be loose/wiggle. torque to correct specs.

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I understand This is of course from the assumption that my torque lever is calibrated. Because my mechanic told me he did not feel tight closing but I still want to compare and test the strength of my torque handle compared to a normal torque handle. Is it true that the lower part of the torque handle range (especially in cheap handles that have not been calibrated for a long time) has gaps of 20/30%? Right? Anyway I bought a new plug set. I drove with my current ones meanwhile only about 2000km. As you wrote I will replace soon. Thank you!

I obsessively use high quality torque wrenches and was under the impression that, as long as I apply grease or anti seize on the bolts, that I could get a very accurate number, it’s when bolts are put in dry that you can be well off. Have I been misinformed? Also, full disclosure, I am very much a hobbyist, so even being off with a good wrench is I’m sure much better than I could do “by feel”.

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All my keys are high quality, however, unfortunately the key torque I had to strengthen the plugs in this range is cheap. I'm angry at myself for using it. The torque of the plug is about 30nm which is the torque of the key 28-210. I estimate the spring is weak and I hope the 10nm addition has been offset due to the calibration of the torque wrench I have. Tomorrow I will do a comparison in front of a quality torque wrench to know how much it really is 42nm of my torque wrench that my garage closed with (it did not feel like it was over tightening according to what he told me)

^^^^this is exactly what I'm talking about! That is NOT an appropriate torque wrench to be using for that torque spec! 1. It is a damn long handle for that torque spec. 2. It is on the very bottom of the torque range, where accuracy falls off even when calibrated. 3. It's a spring operated torque wrench, which does not hold its accuracy very well, especially if not reset to no spring load every time it is stored. 4. It's been sitting in a drawer for years. Buy an appropriate length, appropriate range, calibrated torque wrench for the spec you are torquing, learn how to set/read those cheap vernier type torque wrenches, or just just use a *small* ratchet handle and do it by feel! ---- That said, I think you are fine with your spark plugs. You didn't snap them off, you aren't (presumably) getting misfires, it's very unlikely you damaged the threads (and if you did, replacing the plugs isn't going to fix it). Did you use any anti-seize on the plug threads?

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Thanks!! I will definitely purchase a quality torque wrench for the next replacement. To your question - I did not use any anti-seize. I just installed them and all the plugs closed fine.

1. The right torque wrench 2. Correctly used 3. Correctly set. 4. That is operating and indicating properly 5. And is at least roughly within calibration Is of course better than doing it by "feel". My issue is when someone uses a 17" long lever, torque wrench or not, to tighten a low-torque fastener, and s*** breaks before you even know it. SO MANY times I've heard folks with snapped bolts and stripped threads say "I didn't feel the click, so I kept pulling!... SNAP! ...OH F**K!" With a standard 7" ratchet, the brain kind of kicks in and says "that feels like more than enough torque for this small fastener or low-torque spark plug..." 17" lever? That you think is supposed to tell you when to stop? Not so much. Another example, I've had my uber-fancy SnapOn digital 3/8" unexpectedly turn itself off in between bolt 1 and bolt 2. Without some sense of feel, I could tug forever and of course it would never vibrate or beep.

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For starters Porsche bolts cost $5. & up each!

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Lubricants can alter the specified torque, ideally the spec should specify dry or lube to use.

I just re-assembled the front end of my 2002 996 TT, shocks and shock mounts. I replaced all the lock nuts I could; I am used to have a crown nut and cotter pin ... on the tie rod if you will... but I looked up and applied all the proper torque... GNT is ok for some things, but why not just do it the way Porsche said...

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Hi I will update as I promised that I think that luckily the torque handle I tightened with it as "42 nm" (supposedly) is not calibrated and its spring is tired. I checked in comparison to a small, high-quality torque handle from a well-known company (but both old and uncalibrated). I tightened with it about 25nm (standard 13 screw) and after that I used a torque handle with which I closed the plugs - I tightened 42-44nm and this caused the screw to move barely 1/4 turn .🙏🏼 It's important for me to note that I appreciate that even the small quality torque handle I have that I compared to it is not calibrated so its 25nm is also less. My conclusion. I must act as you mentioned. In addition, I will replace my plugs at the next opportunity in the next maintenance treatment before the 20,000km has passed.

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Porschetech3 - I have an Update :-) Happily - I checked a professional torque calibration institute using a measuring instrument and the results showed that my handle that I tightened with "44NM" actually gives 35NM in the instrument. So I'm fine, right? In any case, I will replace the plugs before the maintenance date (in the near future - using a professional torque handle). THX ALL

Ironically, I ordered this weeks ago, before I saw this thread, just showed up yesterday. Made in USA, range o adjustment 10-50 INCH LBS. Right tool for the right job, per some earlier posts, don�t feel comfortable when a wrench is at the top or bottom of its adjustment range. All of my Torque Wrench�s are this brand, tension released after each use.

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Just what I need to get. Good n tight is not good enough when you need more than one fastener on a part. What's the range of this one (hard to see)

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Yes,, you're fine ..

Always use the proper tools

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Thanks Bro🙏🏼

Wait, what? Am I the only one who uses a torque wrench for the the step up in power and performance? You can't discount the gas, oil and repair cost savings either. Just sayin' Seriously though, if I'm torqueing small stuff I use a 1/4" drive beam type if there's room. I think it gives me a better feel with less chance of something bad happening. The 1/2" drive Craftsman beam wrench is shot but I keep it around because it was my Dad's and has sentimental value.

Bill, Here is a link to the wrench in the picture. This one is for light torques, I got this one for low torque applications (10-50 inch lbs) have another 1/4 for more frequent use, as well as a 3/8 and a 1/2 model. Check the specs, think you�ll be impressed. I chose all inch lb models and just do the math to ft lbs and NM as they offered the most incremental adjustments. Just my OCD I guess. https://www.tooldiscounter.com/produ...ench-prem1f50h

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Is that the "Strip to yield method"?!! To the OP, Buy a torque wrench, these are well built machines with allot of dissimilar metals in structural situations, Steel bolts of various grades into aluminum all over the car. What's more important than brakes? You definitely need to torque your wheel bolts anyway, or risk warping rotors. One of which costs more than a decent torque wrench. For the sake of the next owner, if not yourself, do it right.