Torqueing lug nuts

Sublimewind · Post by **Sublimewind** » Fri May 25, 2007 3:01 am

Hi all,Just wanted to share more info... Mainly regarding torquing lug nuts... If you have done this, you are a good person, if you have added grease and done this... YOU NEED TO READ THIS... http://www.raskcycle.com/techtip/webdoc14.htmlThese charts help define basic torque figures for different bolts and thread pitches It also denotes how LUBE can effect the torque figures DRASTICLY.... I have some first hand expierence with this, as i destroyed a set of lug nuts and a few studs after using "anti-seize" on my lug studs... I actually POPPED the ends out of my lug nuts... (on my Subaru BTW)So i hope you all find this beneficial... Thanks,WindEDIT: As a side benefit to the above, it also helps be less of a factor of warping rotors if the lugs are all in the same tension.... you "can" pull hot rotors out of "true" by improperly torquing lugs and driving hard...

scherry2 · Post by **scherry2** » Fri May 25, 2007 3:44 am

I check the Torque on all of the Air Guns used on the motor line at GM where I work. you wouldn't believe the variables out there that can cause not proper torque. pretty interesting chart thats for sure.

Mavrik · Post by **Mavrik** » Fri May 25, 2007 4:02 am

I have never used any lube or anti-sieze stuff myself and always tighten by hand and then with a torque wrench. Even if I use a torque socket on an air gun, I double check afterwards.Did that with my Vibe and now with my Subaru.off topic... you own a 99 Impreza RS? sweet.

Sublimewind · Post by **Sublimewind** » Fri May 25, 2007 4:19 am

I do in fact own a 99' RS and LOVE it, but she's getting REAL tired, needing a new or rebuild motor BADLY (oil and coolant leaks du to crappy head gasket design)I noticed your rockin an STi, congrats and the wifee a LGT very cool and up in alaska, very cold... are you a member of NASIOC.com? If not, you should be... Cheers..

Mavrik · Post by **Mavrik** » Fri May 25, 2007 5:22 am

Quote, originally posted by Sublimewind Â»I do in fact own a 99' RS and LOVE it, but she's getting REAL tired, needing a new or rebuild motor BADLY (oil and coolant leaks du to crappy head gasket design)I noticed your rockin an STi, congrats and the wifee a LGT very cool and up in alaska, very cold... are you a member of NASIOC.com? If not, you should be... Cheers.. Yes I'm Mavrik on NASIOC since like june 2005. Its not cold up here right now... was rocking sunshine and 70 the other day. Yeah those headgaskets on the older ones are not the greatest...

vibe-04 · Post by **vibe-04** » Fri May 25, 2007 10:30 am

Nice post! And yes, if you never, never, never oil any mating bolt/nut. We learned this back in college as one of the biggist no-nos. Now, some bolts that require torque can't be avoided (oill pans transmissions etc) but an oiled lug can literally back off with vibration or resonance.If anyone here is serious about automotive engineering I reccomend the Bosch Engineering book.http://www.amazon.com/Automoti...06694 It explains everything about automotive engineering like torque.I 'm going to order the latest copy mine is lost and I graduated in 91 so its out-of-date.Later...A

Sublimewind · Post by **Sublimewind** » Fri May 25, 2007 10:26 pm

Thanks for the addition vibe-04..!!

Raven · Post by **Raven** » Sat May 26, 2007 4:58 am

Quote, originally posted by Mavrik Â»Yes I'm Mavrik on NASIOC since like june 2005. Its not cold up here right now... was rocking sunshine and 70 the other day. Yeah those headgaskets on the older ones are not the greatest...I know. Mine are leaking on my '97 Outback. Also the camshaft seals seem to be an issue.

Sublimewind · Post by **Sublimewind** » Sat May 26, 2007 10:35 am

Quote, originally posted by Sunny Â»I know. Mine are leaking on my '97 Outback. Also the camshaft seals seem to be an issue.yeah, there another Subaru issue... I just changed mine with all my timing belt gear... If you get to the point of doing the TB make sure you add in the cam and crank seals as well...

Sublimewind · Post by **Sublimewind** » Tue Jul 17, 2007 11:37 pm

Bump, Possibly another sticky worthy post?? Yes?

ramenboy... · Post by **ramenboy...** » Wed Jul 18, 2007 12:56 am

great post. i second the motion for sticky

isaaclud · Post by **isaaclud** » Wed Jul 18, 2007 5:04 am

I hand-tighten-loosen EVERYTHING....never sprung for a torque wrench.....but in theory, shouldnt EVERYTHING on a car(or other machine for that matter) be tightenedwith a torque wrench? ....just a hypothetical question....

Sublimewind · Post by **Sublimewind** » Wed Jul 18, 2007 5:54 am

Yep, in theory.... the main issue with torque and lugs is getting them even.... they could be at 50ft/lbs or 500 as long as they are even.... There are MANY other factors, but this was just geared toward lugs...

WaveAction · Post by **WaveAction** » Wed Jul 18, 2007 6:14 am

i only use a torque wrench..how much pounds would be the ideal for the vibes..100??

guilty · Post by **guilty** » Wed Jul 18, 2007 6:43 am

76 ft/lbs.

prathman · Post by **prathman** » Wed Jul 18, 2007 6:52 am

Quote, originally posted by Sublimewind Â»Yep, in theory.... the main issue with torque and lugs is getting them even.... they could be at 50ft/lbs or 500 as long as they are even....The units of torque are lb.-ft. (you multiply the force in lbs. times the lever arm in feet; "ft./lbs." would imply that you divide them). And the spec for the Vibe lugnuts is 76 lb.-ft. so trying to go up to 500 is likely to snap the studs off no matter how evenly you're doing the tightening.

Whelan · Post by **Whelan** » Thu Jul 19, 2007 12:03 am

I believe our cars in the 80-85ft. lb. range, but this is off the top of my head. I typically let the place who installs or rotates do it for me, they set their torque just right. It also helps to go back and double check the torque a few days later just to be sure.

engineertwin2 · Post by **engineertwin2** » Thu Jul 19, 2007 12:51 am

Quote, originally posted by Sublimewind Â»Yep, in theory.... the main issue with torque and lugs is getting them even.... they could be at 50ft/lbs or 500 as long as they are even.... There are MANY other factors, but this was just geared toward lugs... The statement of it being 50 or 500 is not necessarily true. It is dependent upon the diameter and grade of lug stud being used. However, I think that what you were implying was that what they torque to isn't as important as ensuring that they are evenly torqued.Unfortunately, this statement isn't true for lugs that are over- or under-torqued. Yes, it is important that they get torqued evenly, but failure to torque them enough can result in wheel wobble and eventual failure (snapped lug studs would be the best you could hope for). Over-torqueing tends to have the same effect - you destroy the threads and can cause failure much sooner. As has been experienced on our cars, the fracture point for the lug studs is not significantly higher than the torque spec on the lugnuts themselves.

Sublimewind · Post by **Sublimewind** » Thu Jul 19, 2007 3:52 am

Quote, originally posted by engineertwin2 Â»The statement of it being 50 or 500 is not necessarily true. It is dependent upon the diameter and grade of lug stud being used. However, I think that what you were implying was that what they torque to isn't as important as ensuring that they are evenly torqued.Unfortunately, this statement isn't true for lugs that are over- or under-torqued. Yes, it is important that they get torqued evenly, but failure to torque them enough can result in wheel wobble and eventual failure (snapped lug studs would be the best you could hope for). Over-torqueing tends to have the same effect - you destroy the threads and can cause failure much sooner. As has been experienced on our cars, the fracture point for the lug studs is not significantly higher than the torque spec on the lugnuts themselves.Agreed, the post was more for demonstration purposes and laymen example. Even torque IS the idea, proper torque is the RIGHT idea... They are designed with an amount of "range" but being under or over can lead to failure. I've been on both sides of the spectrum. I've over torqued (using grease) to the point that i broke out the ends of my lugs AND streched the stud, never broke one, but, streched to the point that you could see it in the threads... I've also lost lugs due to not re-checking the torque after 100mi or so (you should check at 100 and 500mi to be safe, with aluminum wheels, not so much with steel) I personaly have never broken a lug stud, unless it was rusted to the lug... but, at the same time, i haven't worked on a Vibe yet either...

Torqueing lug nuts

Torqueing lug nuts

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