Lug nuts backing out?

[APKhaos]

Baseline:
- I torque the lug nuts every time, so they are installed at factory torque settings

Despite that, every year there's a least one case where the lug nuts back off to the point where the wheel is banging around on the studs. If this had happened once I'd put it down to some idiot [me] not torquing them correctly. Its happened several times, and the only driving this baby gets is highway and local cruising.

Just wondering if anyone else has seen this problem or has any insight.

 

[phsycle]

Only thing I can think of is if you have debris where the lug nuts seat? Are you on factory wheels? How much did you torque them down?

 

[SouthernSS]

use some blue loctite on em and never worry again.

 

[gaijin]

Sounds like you might be using flat lug nuts where conical are required - or vice versa.

I'd double check that you are using the correct lug nuts.

 

[APKhaos]

Factory wheels, no unusual junk under the lugs. Locktite on lugnuts? Don't think so.

 

[spressomon]

FWIW...with all the on/off cycling of my 100 wheels over the years I've found 120ftlbs to be better. I suppose the mating threads for lugnut and stud just get worn a bit...no problem since going with a little more oomph though.

 

[Trunk Monkey]

What are you torquing them down to? Hub or other wheel issues causing them to vibrate and back off? Blue loctite is the stuff you can break off, but it would be a band aid in this case, I'd track down why.

 

[APKhaos]

Might up the torque to 120 as spresso suggests. Been on the light side at 100. Everything else is normal [no thread or lug damage] so we'll see how they go with more grunt.

 

[Supra88]

I've always torqued the lugs to 100 and am amazed at how loose they are when I remove them. I'm going to up the torque to 120 as well.

 

[2000UZJ]

I run mine at 120-130lbs. I have never had an issue.

 

[SouthernSS]

blue loctite is made to come off without any heat and is used in assembly parts all the time. it withstands vibrations very well. Normally you wouldnt use it, but in his case, it just may be the ticket. Over torquing your lugnuts is a good way to warp your rotor or wheel bearing flange. You also risk stretching the lug threads beyond the breaking point at which point you'll just lose the whole damn thing if you hit a good pot hole.

But what do I know eh? I'm just a guy on the internet. Torque them to 250!!!

Dont really do that.

Try going to 120ft/lbs and see how that does.

 

[agaisin]

spray down the threads and lug nuts w brake cleaner to make sure they're clean with no grease!
also, your torque wrench may be bad - have it tested.
I have to believe either there's grease residue on the threads or lugs (perhaps leftover from sloppy wheel bearing job etc) or you're trusty torque wrench says 100 but is faulty/out of spec and maybe only torquing to say 80...

Sent from my iPhone using IH8MUD

 

[gaijin]

I still think this problem is due to using the wrong lug nuts.

Any pics of the wheel and lug nut combo? Prefereably close-up of the mating surfaces.

Factory spec torque is 97 - should be plenty if everything (nut, wheel, torque wrench) is in order.

Simply overtorquing to 120 is not a good idea.

 

[spressomon]

M14 max recommended torque (dry threads): Grd 10.9: 131lbsft / Grd 12.9: 158lbsft.

agaisin makes a valid point about torque wrench accuracy/calibration. I can't confirm if my torque wrench is 100% accurate or not. Just went out in the garage and mine were all torqued to 115-118lbsft. Been doing it this way since putting the 35's on in '06

I found, running 35's, the factory recommended torque for our lug nuts of 96.6lbsft, was not getting the job done; I doubt the Toyota engineers based their recommendations on 35's. 222/242 Loctite or increase the torque...that's your choice if you run into the same issue.

I don't have issues with lug nuts working loose nor issues with lug nut torque induced damage to the rotors nor any other negative issue with running the lug nuts at 115-118lbsft.

 

[scottm]

Millions of cars on the road and torquing the lug nuts/bolts properly works fine for them. Few people had torque wrenches a generation ago, people used to routinely change their wheels at home without a torque wrench, epecially in snow country. Even if you approximately hand torqued, they should not be falling off. Something is not right with your setup. Have you verified you have stock lugnuts and wheels? Has it been the same wheel each time, maybe there is a crack in it or the hub behind it?

 

[scottm]

Lug torque is based on how much stretching force the lug stud can take. The studs get force applied by torquing the nuts, then more force during cornering while hitting potholes etc. Engineers add up all the forces in worst-case driving scenario, plus a safety factor, then select a stud size that allows for that much force along with the force from the standard torque for that size stud. Adding to the torque means reducing the additional forces required to snap the studs. I doubt any of us are going to snap a stud, but I don't recommend going higher on torque in hopes of increasing safety.

 

[SouthernSS]

^---- bazinga

 

[spressomon]

I get the math. If we are going to analyze our rigs purely from a safety engineering perspective we are going to need to look well beyond lug nuts. Raised suspensions, larger diameter tires, non-absorbing bumpers, GVW well in excess of the rig's OEM engineered capabilities, etc., all must be scrutinized. And if we do that we'd all be driving stock rigs

Just sayin.

 

[hoser]

Despite that, every year there's a least one case where the lug nuts back off to the point where the wheel is banging around on the studs.

I have no clue but here are some question that might help:

Is it the same wheel that loosens? Or the same position (i.e. DS Front), every time? Maybe mark that particular wheel and keep track.

Have your wheel(s) been refinished... perhaps too much paint/clearcoat at the lug nut mating surface? Are you sure all your wheels are OE and not knock-offs? Are the lug nuts/studs OEM? I think I remember seeing OE style lug nuts but with different dimensions.

 

[TrekboxX]

Millions of cars on the road and torquing the lug nuts/bolts properly works fine for them. Few people had torque wrenches a generation ago, people used to routinely change their wheels at home without a torque wrench, epecially in snow country. Even if you approximately hand torqued, they should not be falling off. Something is not right with your setup. Have you verified you have stock lugnuts and wheels? Has it been the same wheel each time, maybe there is a crack in it or the hub behind it?

Agreed. Actually, millions of cars on the road with the lugs torqued "improperly", and they don't have (many) problems. I'll admit I've never torqued lugs with a torque wrench. Just use common sense. I've never seen a mechanic or a tow driver(literally watched thousands of tire changes) use one, either. I'm not advocating going without a torque wrench, you make your own decisions, but just pointing out that it doesn't NEED to be exact. I've seen more problems with over torquing, such as the Toyota dealer that jacked up two of my wheel studs last year. My guess in your case is under torquing or foreign material between hub and wheel. Hope you get it sorted asap. Bad news when the wheel comes off on a top heavy SUV.