Stretch bolts reuse Too many people use the term and make an assumption that they therefore are not re-useable, which of course does not happen unless thay are over tightened. If they're only torqued to a specific value and not turned an extra amount you should be fine. Nov 1, 2016 · I'm in the middle of a clutch job. Do I need to (or should I) replace the crank bolt or can I reuse the old one. Although vendors like idparts conveniently packages together the bolts you need for a job, Genuine VW bolts are expensive. SirWired Sep 9, 2016 · “Reuse: ASTM A490 bolts and galvanized ASTM A325 bolts shall not be reused. Was about to re-install the flywheel when I ran across a post by someone saying that the bolts had to be replaced because they are stretch bolts. Then put in the other 2 pair. Jan 25, 2002 · Re: Re-use Head bolts (ncvwnut) "Stretch bolts" is not really the correct term. You know what happens when you stretch the bolt on a toe link? You eventually end up with 3 wheel steering, which sounds really cool until you realize you only get to control 2 of them, and you end up in a concrete Each one costs 11usd with no aftermarket options. bolts; these bolts are designed to stretch, and reusing them will cause improper, uneven torque and clamping force (never reuse T-T-Y head bolts). Same with Dog Bone bolts. Jan 3, 2003 · The Case For Stretch Bolts. It only took ONCE (on a B series motor) where I reused the bolts, and they happened to be past that re-usable point and it ended up stripping the aluminum thread of the block. The original VW stretch bolts will be very expensive to order for me, when I could get "regular" bolts with same dimensions/threads for a fraction of the price. 4TEC manuals up to 2005 say you can reuse them. im sure someone has a story about how someone they know reused a stretch bolt 17 times and had no problem, but hey thats the internet for ya Mar 12, 2008 · Ask any subaru technician they wil tell you to reuse the bolts. Especially after you did all that work to your engine. Torque to yield bolts are designed to stretch more. Stretch bolts (also known as torque to yield) typically have a "turn of the nut" tightening process, since torque isn't reliable when they are stretching. Dec 4, 2009 · Do Not! DO NOT, reuse rod bolts! Take it from me, they are stretch bolts and should not be reused. Put some treadlocker on the caliper bolts if you use the old ones. 8l 24v VR6 Engine Forum Stretch bolt re-use May 11, 2008 · Its not cheap insurance, its the proper way, reusing old stretch bolts is simply asking for problems I really dont care how many people have said they reuse their old stretch bolts or dont replace nylocs. falcon head bolts are torque to yeild which means when they are tensioned up they stretch to get maximum clamping force and dont stretch back when unbolted. Thx Jul 13, 2016 · I was also taught a lot about fastener grades, their in house testing procedures (you should see the machine that pulls a 1. also many have a one time only are a special galvanized type , have a heavy blue or red locktight coating or also have a crimped nut welded to a handle like holder to allow May 31, 2009 · Absolutely need replacement as they are stretch bolts. Depending on the type of fastener, materials used for both the bolt and the part it screws in to, cleanliness of the thread, lubrication used, TYPE of lubrication used, etc. And serp-belt wheels on crank shafts. teespring. Do Expert Mechanics Recommend the Reuse of Flywheel Bolts? Absolutely. of the shaft of the bolt, appears to Jan 8, 2015 · Perhaps read my post properly next time; I said "they are no more stretch bolts than any other type of bolt" and as such, they are - all bolts stretch when tightened fully. I would put all crank bolts in starting with the outer pair of bearings and torque. It's not fear and mythology in my opinion. The service manuals make a habit out of telling people to replace bolts that don't really need to be replaced. -Charlie May 9, 2005 · > engine. May 12, 2010 · It appears that the bolts holding the bracket to the blocks and head are not stretch bolts and will be reused. oh and someone also said they put motor oil on the Nov 23, 2009 · i would NOT reuse head bolts. com/Today we test various myt Nov 9, 2004 · DONT REUSE THEM. then they can be reused, but if it says torque to 72ft lbs. And other things like that. Just because they didn't break until the torque you stated doesn't mean they don't stretch/change before that time. I guess peace of mind is measured in bolts replaced Oct 6, 2014 · 2. They are designed for multiple stretch applications. 3. Nov 5, 2010 · 2. ) The steel is probably not designed to be stretched twice. It is therefore beneficial in high-frequency high-load situations with a higher risk of fatigue related failure, like a bolted down cylinder head, to use torque to yield bolts. NOTE: Torque To Yield bolts are actually stretched BEYOND the elastic zone (they will not stretch again) these are ALWAYS Jul 13, 2013 · My Jetta has been running on re-used LCA bolts going on 4 years. Turn again. You can safely replace them with grade 12. Nov 10, 2013 · I know some head bolts are yeald an stretch an when used so they can't be reused. Feb 20, 2011 · I find hard to believe that a bolt will stretch after it deforms the locking nut The "stretch bolts " saga has gone overboard when Bentley calls for bolts that thread to aluminum threads to be replaced . Is it possible that the > 20R engine does not use stretch bolts and it is ok to reuse the old > head bolts? > > Thanks, > > Greg Shortridge Jul 20, 2005 · Torquing with just torque values such as foot-pounds or newton-meters is at best a guess at getting the torque correct. Stretched bolts can yield in the threaded portion or the shank portion. And yet another paragraph: Apr 2, 2006 · What do you all think about reusing stretch bolts? You know, the funny-colored bolts that hold on miscellaneous little things like engine mounts. If the T-T-A bolt’s reusability is in question, replace it. If you over-torque them, that will lead to stretching. At Bimmerforums, you will find technical how-to information maintenance specifics audio advice wheel and tire combinations and model specific details not found anywhere else. Our professionals are here to help make sure you find the answers you need to your questions and our community is here to help other brainstorm Aug 6, 2013 · You can reuse the head bolts just fine. Reusing a TTY bolt causes it to not be preloaded, which inturn defeats its natural resistance to backing out. etsy. They are not TTY bolts as they start out but they are torqued to TTY specs so the bolt stretches when torqued. Mar 17, 2012 · risk of reusing stretch bolts? Jump to Latest 18K views 4 replies 5 participants last post by Aseras Mar 21, 2012 Feb 13, 2014 · First - there HAS been a change in bolt technology, and there are now what are known as TTY or Torque-To-Yield bolts, where the bolts are torqued until they actually stretch (or yield) and are permanently elongated - this type of bolt can/should not be reused - I believe you will find that TTY bolts (also known as angle torque, for reasons that are about to become clear) have a different Sep 23, 2008 · 4 Cylinder Engines - Reusing Torque to yield bolts - I will be replacing a head gasket on another Escort 1. The ones I would absolutely replace every time: steering rack bolts; subframe bolts; axle nut/bolt; control arm bolts; Anything else, whatever. Yielded bolt threads can damage threads in the engine, especially on aluminum blocks, and since the bolts are weakened, they may Jul 7, 2012 · This is made easier if you face off the threaded end of the rod bolt. that being said remember you wont need to go by the book for tightening them because the sequence they give is for new bolts that need to be stretched. I have reused stretch bolts on occasion however I try not to. The bolts are 10. If in doubt, best to follow manufacturer recommendations. you should be able to see the shaft of the fastener, with the threads clearly sticking off. they just reuse everything, but it's my understanding that anything that gives it's torque spec as XXlb/ft plus YY degrees to tighten it is a stretch bolt. Edit: this is not a recommendation unless you are going back in and will eventually replace. Jul 20, 2009 · The reason that ‘stretch bolts’ are used in some critical bolting applications is because that ‘yield point’ of the steel is a known value — it is a material property, not affected by the joint or the thread friction or the day of the week — and when that stretch bolt is tightened correctly, the clamping force can be guaranteed with Jan 13, 2023 · I cannot delve into the mindset of Porsche when they make these requirements. I spent a lot of time wearing down two or three cutters in the process. I wanted to use a new set of head bolts, but I am unable to > find any for sale. Jul 16, 2013 · This applies to all torque to yield bolts (Stretch bolts), meaning the bolts stretch to ensure proper securing when tightened down. 2-0. Some oil pan clearance is necessary, but it's quite easy and just some webbing that gets cut. Jan 18, 2009 · While putting loctite on the caliper bolts makes sense (they aren't stretch bolts), aren't the axle bolts stretch? I would be wary of reusing those (or any other stretch bolts. Apr 8, 2012 · Bimmerforums is the preferred online BMW Forum and community for BMW owners. All bolts stretch, thats how they stay tight. Snapping bolts, breaking knuckles, lots of cursing!! My question would be if you replace stretch bolts with regular high-strength bolts, how do you come to a final torque value? However, because the tightening procedure does permanently stretch the bolt, there is some risk of breakage if the bolt is reused. com Apr 4, 2005 · Standard stretch bolts require a certain amount of art. Now 30,000 miles later I have a softball sized hole in my block where the rod cap came thru. They've been re-used over and over at every TB job on my Jetta. They are preapplied with treadlocker, green stuff. I would Dec 19, 2010 · Cam gear bolts arent stretch bolts. Remember, bolt stretch, is how we get maximum clamping load. Mar 5, 2012 · First, the rear bolt, is in fact, a stretch bolt. It looks to be in perfect shape. , the torque between two "identical" fasteners can actually vary by as much as 35% (or more) with the Stretch bolts for cylinder heads Stretch bolts, or torque to yield bolts, when properly torqued, loose some of their diameter to the stretch, but are elastic, and if variations in the gasket material or other things occur they keep their clamping force by varying their diameter slightly, but frequently, like breathing. CCR engines will tell you they reuse the bolts. Dec 22, 2020 · well and i'm sure someone will pipe up and do the ho know the end of the world will happen if dont replace them etc, on head bolts deffo never reuse them,, i have reused the conrods and mains bolts and use max strength loctight and important use brake cleaner on both threads and i only stretch them the second time by half ie if says 180 degrees do 90 degrees etc, never reuse the camshaft bolts Nov 7, 2004 · Unless the factory service manual says you can reuse them, don't. com Our Tee store: https://torque-test-channel. Although any bolt that requires a 1/4, 1/2 or whatever turn after torqueing it, is a stretch bolt, which stretches or torques to the bolt yeild. yes people have reused them with little failure but there have been some failures it cost 30 bucks to order the two kits needed from ECS. This makes using the stretch method difficult. When reusing my BBS bolts for my wheel I was told to go less than half of what the original spec was but idk what the reused specs might be on axel bolts. May 11, 2006 · Re: Reusing Strecth Bolts. When approved by the Engineer of Record, plain finish ASTM A325 bolts are permitted to be reused. Subframe Stretch bolts which were installed, taken out and re-torqued within 5 minutes. When Triumph stopped using bolt measurement to tighten the rod bolt, they slowly stopped machining the threaded end of the bolt flat. Feb 13, 2006 · I haven't reused them. Standard stretch bolts depend on a lot of feel / knowledge or complicated tools to get past the human element. Re-use of Fasteners and Torque In the event that a fastener is reused, attention must be given to the method of reinstalling the fastener. However, TIS says nothing about replacing the bolts anywhere. Fortunately I caught it and fixed it before additional problems resulted. Yes, you CAN reuse them, but they're stretch bolts (or nuts, in some cases). Standard stretch bolts do have a service life. 5" bolt until it snaps in half), and many other things related to bolt stretch, torque curves, and the like. If you are using the old style head gaskets (although I don't think anyone even sells them anymore) you can reuse the old bolts, even though most agree, it's penny wise, pound Jul 4, 2018 · Caliper bolts to 25. My intent was to make a custom punch for a specific job I was doing. Apr 12, 2023 · However, some manufacturers may provide specific guidelines for bolt reuse based on the application or bolt type. I did one of these cars about a year ago, and replaced the TTY head bolts and had the head reconditioned at a shop. Oct 8, 2017 · The bolt strength is the concern here by using it a second time. If the book says torque to 72ft lbs. Jul 20, 2005 · Torquing with just torque values such as foot-pounds or newton-meters is at best a guess at getting the torque correct. "stretch bolts" theres your explanation right there. look up ast the top, where the threads meet the head of the fastener. Inspect threads on the strut top hat bolts and the brace bolts if you're going in there. You should always replace the bolts. ReferenceDesign Veteran Member. The cap bolts is an easy replacement swap out new bolts with the old one. Dogbone 4. 81 ft. Thread starter ReferenceDesign; Start date Jul 1, 2011; R. Well, if Bentley says they're stretch bolts from the factory, then you shouldn't reuse them. [ citation needed ] The torque applied to the fastener must be determined such that it does not contribute to a service condition where the fastener enters a low-cycle Jul 22, 2023 · Here is a suggestion to try to identify if crank bolts-Do not put in the case bolts until after testing crank bolts. 55mm and im thinking about keeping the bolts that are under 0. Generally, Torque to yield bolts have cut down shanks whereas the VW headbolts have full diameter shanks. think of it like this, if you take a thin piece of steel and bend it one way and then bend it back the best you can, is that piece of steel as strong as it was before you bent it? its the same exact principle. May 21, 2016 · that is correct, most bolts used on todays cars are a one time only and should not be reused, they can fail as they are no longer capable of properly holding the torque. Because, the larger a bolt is, the less it will stretch. plus 1/2 a turn then they are stretch bolts and should not be reused. Feb 21, 2017 · fasteners can be reused, contact the FEDS department and we will provide assistance. Nov 3, 2023 · Bolts do their job by STRETCHING and remaining within the elastic zone to keep things pulled together tight. preview. Aug 1, 2002 · We all know that VW loves torque-to-yield (stretch) bolts, and they are supposed to be replaced with new bolts every time they are removed. Once you stretch them, you've weakend the metal, do it again Mar 17, 2017 · This video from Fel-Pro illustrates TTY bolt stretch and why you can’t reuse a torque-to-yield cylinder head bolt. I'm also running a re-used center Crankshaft bolt (the twelve point bolt). 4. Is this really a big deal. Jun 4, 2017 · Thanks for replying. We also still recommend doing main studs, partially for the added strength, partially for the fact that they can be reused over and over. . The tq spec is 52ft/lbs +90*. My last car wasn't, but then again someone could've replaced it. You can usaully tell by the torque rating whether this is true or not. TTY bolts MUST be replaced. i would reccomend it. The caller carrier bolts need MUCH higher torque and then turned an additional 1/2 to 3/4 turn so the bolts stretch. There is a TSB someplace that says to reuse the bolts. On the other hand , the rocket bolts didn't look stretched at all T-T-A bolts should always be inspected before their reuse to make sure the threads are in good condition and have not been stretched. They take the beating and heat of combustion. kinda like the clutch and flywheel bolts the only time i ever reused them my friend said he never replaces them so i didnt and they broke had to pull the trans again and get new bolts and another clutch Aug 27, 2020 · They can be reused, exception are the stretch bolts which will be stretched into the plastic region. It does suggest that the bolts TTY bolts can stretch beyond their yield point; therefore, most manufacturers recommend discarding them after removal. Jul 1 Jul 17, 2023 · You can only reuse a flywheel bolt if it is not the "torque-to-yield" type and is currently in good condition. Apr 4, 2015 · "The axle bolt is a torque to yield "stretch bolt", tightened to 70 NM/52 lb ft. Sep 21, 2021 · In almost every application, they are stretch bolts which cannot be reused once they stretch to a certain point. The bolts can be expensive, but failure to replace them can lead to stripped threads, broken bolts (hard to remove), and a costly comeback (leaking cylinder head gasket). (misfit77) personally i wouldnt reuse em, but if i had to or was going to it would be only once. If you reuse them the structural integrity will be compromised from the deformation in the initial installation and then further deformed at the subsequent installation and will likely fail. Failure to coat the threads may allow coolant to leak past the bolt. I have muscle wheels coming an want to swap stuff over. Lotus VERY explicitly advises against reusing them or against tightening them if they come loose because you'll stretch the bolt. The science here is irrelevant. You need a flat surface that is square to the shaft of the bolt to do this accurately. This allows for calculating exact clamping force by knowing exactly how far that bolt is stretched. Jan 17, 2004 · VW uses normal fasteners at TTY torque specs. Sea Doo changed their recommendation in 2006 because of poor training at the dealer level. You can re-use it once or twice, but the stretching causes the bolt to stress, and wont hold correctly. , the torque between two "identical" fasteners can actually vary by as much as 35% (or more) with the Dec 11, 2013 · Stretch bolts change torque specs when reusing also. Upon reuse, a nut and bolt combination will require an increased torque value to reach the desired clamp load. There are two terms related to this May 22, 2009 · If you are replacing the old waffle steel gaskets with composite gaskets, you need to use "stretch" bolts, and tighten to a different procedure than simply torquing them. Should I have loosened all the bolts and started the torque proceedure all over again or will I be ok? I know the service manual says only reuse the head bolts once, so if I release tention and re-torque the bolts again, it will be three times. Only issue is that elastic status get lost due to processes in the material level, sort of plastic relaxing, which makes the bolt longer and let it lose yield strength. "Torque to yield" is the correct term. Also alignment is fiddly. Touching up or re-tightening bolts that may have been loosened by the installation of adjacent bolts shall not be considered to be a reuse. Perhaps you already know this but they are stretch bolts and when tightening they are torqued to a certain ft-lbs then turned an specific number of degrees. I'm a mechanical engineer and I stayed at a Holiday Inn so my 2 cents worth would say that are not a stretch bolt. In contrast, T-T-Y bolts are tightened to their yield point, stretching them to the point that there is a permanent loss of elasticity. The problem with reusing is you either have to put less torque on the bolt and risk less clamping pressure or retorque to specs and risk having the bolt break. Oct 4, 2009 · Re: (TheMajic86GTI) i reused them once cause i didnt pay attention and didnt realize they were stretch bolts so ever since then i have always replaced them. The new one was late in shipment. Some of these bolts can be reused, if you torque them to the same torque that you would use for a normal bolt of the same size, pitch, lubrication factor, and strength See full list on usefulcarstuff. That's the issue, it doesn't say anywhere I've found or get mentioned in any how-to's, YouTube videos etc. I had a gear in ny tranny changed under warranty, the dealer of course had to take the tranny side engine mount off, they reused the stretch bolts and now 10k miles later the motor mount twisted, I did need new bolts but I said F it and bought myself some Vf engine mounts :thumbup: Lifetime updated tool rankings: https://torquetestchannel. What is relevant is the avaricious cheapness at work by the same crowd of people who want to reuse flywheel bolts, rod bolts, and axle nuts. Apr 21, 2015 · The only bolts I ever worry about replacing are stretch bolts. Starting the bolt turning, takes more force than keeping it turning. they are lengthed during that process so if you simply repeat they won't be at the correct torque and will be weaker. Yes (35Nm). 100's of people reusing the bolts. Oct 22, 2014 · Doing the timing chain guide replacement. That was 6 years ago! I'd never risk re-using motor mount bolts. Nov 23, 2009 · i would NOT reuse head bolts. That makes it a TTY bolt. > > I have always used new head bolts on other cars because they were > "stretch" bolts and could only be used once. I would not hesitate to reuse these bolts and never had to for I don't know how many cars I've owned (BMW, Audi, Volvo). BMW 3-Series (E90 E92) Forum > BMW E90/E92/E93 3-series General Forums > General E90 Sedan / E91 Wagon / E92 Coupe / E93 Cabrio > Reusing Control Arm/Tension Strut Bolts Google Search Search Forums Jan 5, 2014 · Stretch bolts are really tough. , then another 90 degrees to stretch it. Feb 15, 2019 · In that thread another forum member recommended some subframe inserts to stop any subframe/chassis movement and whilst reading about installing the kit noticed that although the manufacturing company recommend replacing the subframe bolts they also say that if you do decide to reuse the subframe stretch bolts to use locktite on the thread. Joined Jan 3, 2003 Location Atlanta, Ga. Feb 5, 2019 · I had one of the two large bolts beside the coolant ball break on my old golf so that the engine was being held by just one bolt. Standard stretch bolts may need to be re-tightened. I'm kind of surprised that they are. ” Apr 1, 2009 · I work for subaru and I have done hundreds of motors and have yet to replace the bolts nor has any of the other techs. Oct 12, 2012 · For head bolts that extend into a coolant jacket, coat the threads with a flexible sealer. A torque-to-yield bolt means that a bolt is designed to be used only once. I thought I'd replace my rings in my engine and reuse the bolts. When you buy OEM pads the caliper bolts are included. Call one of the on line suppliers (1st subaru, subarugenuineparts for example) they will tell you you can reuse the bolts. Can they be changed to "non-stretch" bolts, and if, how do I know what torque spec I should use? Jan 2, 2011 · Well let me tell you a story about those bolts. This is why torque-to-yield bolts use a light torque spec plus an angle for a precise stretch of the bolt. The clamping force of stretch bolts is necessary to retain the inevitable Sep 13, 2022 · The thread pitch of a bolt determines exactly how far it will stretch when rotated a given number of degrees. Apr 10, 2011 · Do I need new ones or can I use the same ones? We werent sure if these were stretch bolts or not? Im ready to start putting the 04 back together but this is the current issue. Stretch Bolts. of torque. lbs. Apr 13, 2005 · Replacing stretch bolts with non-stretch bolts is possible, however the replacement bolt must be a higher-strength bolt, and a new torquing procedure must be calculated, since the old one will not apply anymore. I consider myself somewhat versed on the topic. You Kidding Me right There stretch to Yield Never reuse stretch to Yield Bolts Never. Second, the only way that bolt is going to back out on you, is improper installation/reuse. In this case, I would think it would be safe to re-use, especially being a new vehicle, and no rust issues yet. The tighter the bolt, the more stiction, can affect torque readings. Feb 5, 2011 · The new ones that typically come with CV boot kits are fully threaded and act as the VAG tool to help remove the CV joint from the axle- pop the ball joint, remove the Axle bolt, pull the axle out of the hub, swing the strut/hub out of the way, put the new bolt into the cv joint and tighten until it spreads the CV inner circlip- loosen and pull off your CV joint. Caliper mount bolts I really think it could be the stretch bolts though, because I've never had a problem with any of the others and always driven it hard. And since there is no way to tell how many times a bolt has been reused, it doesn’t make any sense to reused TTY bolts – the risk far outweighs the replacement cost of used bolts. Always consult the manufacturer’s recommendations and exercise caution when considering the reuse of torque to yield bolts. id rather spend $30 on a set of new bolts than have to pull the head off again. Stretch bolts must not be reused, all bolts stretch but a stretch bolt is stretched beyond the elastic zone into the plastic zone. 5% stretch for comparison mercedes says that headbolts under 2% stretch can be reused so im very tempted to reduce cost. You may have to finish the bolt ends so you have a nice true length to measure. Finally got the crank bolt off with a brand new snap-on 1/2" impact gun (that has a breakaway force of 1100ft/lbs). Feb 13, 2015 · Most of them are stretch bolts - so you should replace them. May 3, 2009 · The "stretch" in stretch bolt (which they are) deforms the bolt. This kind of bolt is not recommended for second-time use because once its maximum yield strength is reached, it will not hold up as well as if it were new. Non of them are stretch bolts. I even acknowledged that the bolts would re-stretch to their original length. Jan 16, 2013 · One of the advantages of reusing the stretch bolts is they are perfectly set square to the shoulder and thread as they have being pushed into yield ( conformity). When I have been to subaru training the never said they needed to be replaced either. Unfortunately, using a larger diameter bolt, is not the answer. Yes VR6 does make a difference, the 4 cylinder cap bolt in the Bentley manual doesn't specify replacing this bolt. I can see stretch bolts working better at holding themselves in place than plain steel bolts. I read some where that some parts say new bolts an the only thing is the new ones come with lock tite on them. I'll add that many of the lower torque bolts (say 25nm) can easily be stretched with just 5nm additional. 9L engine, and although it's not a truck perhaps I can get some advice about it here. They are probably stretch bolts. 4mm stretch Thats Less than 0. Yeah, Nuge, I always reuse the pressure plate bolts. This applies to the whole vehicle, as my father told me when I first started driving, I can replace the car but I cannot replace you. Feb 17, 2007 · FWIW, the pentas use the same stretch bolt and have you final angle-tighten them to 120 degrees instead of 90. You can reuse them (why not?). Skid plate bolts 5. 33-ft-lbs of torque. I don't do this, largely because after lightly stoning the cylinder head, there are enough high spots around the head bolts that I think that more clamping is not required or desired. In the VR6 the rod bolts and the main cap bolt requires replacement as per the Bentley manual. 9 metric which is equivalent to grade 8 so they wont stretch or break. reuse it. 9 non-stretch socket head cap screws. oh and someone also said they put motor oil on the Apr 24, 2021 · The low torque needed, and then lack of an additional angle turn mean these are not stretch bolts. These bolts originally are 84mm im measuring stretch between 0. Feb 25, 2018 · Many bolts can be re-used safely, but many bolts cannot, as they are designed to stretch-to-yield torque. Then check for rotation (you may have already done this). Oct 24, 2010 · I did a typical Scotsmans trick-went out and blew R1500 on spares and decided to save a few Rand and to re-use my head stretch bolts:-[ When it came to torqueing them they were fine to 20nm,then JUST managed to get them a further 90 deg,thats with using a power bar,broke two sockets,THEY are tight. I would like to stop paying all Jul 17, 2002 · Bad news when used stretch bolts were reused on engine assembly. Industrial bolts are not very square and will be hard on the aluminum threads. Standard stretch bolts can be over-tightened. Aug 18, 2005 · Re: Good Question: How do you tell stretch bolts from regular bolts? (2kjettaguy) hold the bolt up to the light so your looking at it from the side, and cas see side profile of the threads. I joined in 2002, I feel really old now Feb 28, 2022 · It is important to replace all self-locking nuts, however some A2OC members suggest that the bolts are not Torque to Yield bolts, more commonly known as stretch bolts, and are therefore safe to reuse. Oct 23, 2022 · There is a reason car manufacturers provide you with guidelines on how to torque flywheel bolts. Dec 18, 2010 · All bolts are potentially 'stretch' bolts as long as you can put a micrometer across the length of the bolt unless you mean one time use bolts that know seem the rage in the era of throwaway junk. Because TTY head bolts are permanently deformed once they are tightened, they should not be reused. Jun 22, 2012 · the ECS kit (front kit and rear kit) has all the bolts needed it is not only reccomended for higher milage cars, but for any time you remove those bolts they are stretch bolts. Dec 6, 2014 · I reused the OE bolts when I lowered my cars, torque to 120ft-lbs , I've reused the front LCA bolt numerous times and it hasn't been loose any of the times I removed it. Feb 25, 2007 · So I actually switched 4 bolts total So, my question is. Reusing TTY bolts will cause them to stretch further, which increases the risk of Jul 20, 2007 · Stretch bolts are designed to be elastic, the closer they get to the limit of elastic stretch, gradually more permanent stretch occurs (I don't know the exact relationship); each time they permanently stretch they reduce the maximum clamping force possible (before failure) as the structure weakens each time permanent stretching occurs. Oct 5, 2014 · There are some stretch bolts that I would reuse and others I wouldn't I pulled the PD injectors and replaced the O rings . It’s not just regular car owners who reuse flywheel Since T-T-Y bolts are designed to stretch, reusing them can cause improper or uneven torque and clamping force. if dia. HEAD BOLTS may be the most important fasteners on an ICE engine. Did the job two Days ago on my R. Stretched bolts can damage threads in the engine, especially on aluminum blocks, and since the bolts are weakened, they may break if retorqued. /Peter Good advice above. It just says to torque to 38 ft lbs, wait an hour, and then turn 90 degrees tighter. Using my lathe, I tried to turn down the big long bolt that goes in the lower engine mount bracket. Once flywheel bolts stretch, there is no option but to replace them. The original hold down injector bolts were 1 mm longer than the new ones. but know that they will be incorrectly torqued if you reuse them. I'd personally wait until the next one is due to replace any suspension bolts a few days prior. Feb 19, 2009 · What does the manual say for torque specs? A lot of engines use single use stretch(aka "torque to yield") bolts. (Bolts with Specification: Torque plus Angle). Which LS Fasteners are TTY? On a GM LS engine, the cylinder head bolts are TTY and cannot be re-used. ngdlb snn zpois xtn dqjprmi ihl cufkd ofy agdlb kawbide obr fystabx eisi qghmapq jtga