lug bolt issue

Only 2 possibilities come to mind:

You're getting counterfeit bolts made in China ( aka cheap shit )

or

You're over-torque-ing the bolts. Putting too much strain on them with your lug wrench.

A) go to the Nissan dealer and buy OEM lugs and nuts b) get a torque wrench, set it to the specs for the lug nuts, tighten them in a star pattern, going to 60% the first time around the wheel and 100% the second time around.

While you have the wheel off, clean the wheel where it meets the hub, and wire-brush all rust off the hub that the wheel attaches to.

Word.

Lg

Are you torquing the lug nuts to spec? When you replace the bolts, are you making sure that they are properly seated in the hub before installing the wheel? Can you pull them in without drastically overtorquing them? I'm guessing the originals broke because they were overtorqued by a tire changer with an air gun, but I'm not sure why your replacements would also be snapping.

Is it possible that the tapered seats on that wheel are worn and the lugs are actually snugging up to the hub not the wheel, and the wheel is wobbling ever so slightly even with the lugs tight?

not really sure what the problem is here, just trying to throw out some ideas...

nate

also, check the rim - if the holes are oblong and not round you may have to toss it and get a new rim. Definite possibility if it's been wobbling around on you.

Ray

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I would hope it would be obvious to the OP whether or not his wheel/tire assembly still had *play* ( wiggle ) in it after mounting and torquing the lug nuts.

Every time a front wheel is lifted off the ground, it should be checked for wiggle, in the vertical and horizontal direction, as a test to see if the steering linkage is worn or coming apart.

But yes, I recall Nate asking if the wheel/tire assembly was still somewhat lose after the lug nuts were tightened down, and I don't recall seeing a reply from the OP.

Wheel shimmy can be caused by a multitude of problems, not the least of which is the one you mention, though I have never seen it happen on any car I have driven.

Lg

Lawrence Glickman wrote: ======================================================

I noted that he had had a loose wheel and broken lugs and was still having problems with it. Having had a similar situation and the lug holes were nicely oblonged I thought I'd add this to be double checked. Depending on the rim it's either blatantly obvious, or maybe a bit harder to see. Just one more thing to double check if you're having problems with loose lugs and broken studs. Heck, I'd be calibrating my torque wrench if I had the same problem with the same wheel two weeks in a row. :)

Also, if they're aluminum wheels it may be necessary (and probably a good idea even with steel) to recheck and retorque them after 100 miles or so.

Ray

If you take the wheel OFF of the hub, and use a lug nut, you can drop the lug nut into the lug holes of the wheel and see if there is any protrusion beyond the wheel metal. That isn't hard to do is it? You can feel for any protrusion of the wheel nut, or you can slide a straight edge across the hub side of the wheel and see if it moves the nut at all. Then you know. All the rest is guessing. And people say I make mountains out of mole hills. Much of what I see here is other people making mountains out of mole hills. This isn't brain surgery.

It is just hard to see what is going on. No visuals, no feedback, we're left in an information vacuum. How do you repair something when you get no information.

I had that problem when I drove my Sable home on day 1. There were

6,500 miles on the odometer and I checked the wheel lug nuts. Some were so loose I could take them off with my bare hands. Aluminum Alloy. They look nice, they handle well, but they have to be watched, at least as you say, checked after a few days for possible re-torquing.

Lg

That's only one way it can be blown. It also can still be thick and have oval holes from wear.

These holes will not allow the rim to be hand loose, but allow the rim to shift non the less which will break off the new studs. I have seen that more than a few times over the years.

Mike

86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00 88 Cherokee 235 BFG AT's Canadian Off Road Trips Photos: Non members can still view! Aug./05 (More Off Road album links at bottom of the view page)

Interesting. I've made a note of it. ( i.e. added this post to my notebook along with others )

That would be a shearing force, likely to be most severe during acceleration or braking. I can see it. ABS systems would exacerbate that effect I can imagine.

Lg

not sure about that, but those studs are intended to be loaded ONLY in tension... if there's any shear load at all there's something wrong.

nate

That's why I tossed the idea out. Trying to help people fix cars over the internet is often vague because you can't see the whole picture. Sometimes it's obvious, sometimes it's not. We've already come up with a whack of ideas:

1-incorect torque causing wheel to come loose (too tight/too loose) 2-poor quality wheel studs 3-damaged rim

maybe the OP whacked a curb and "forgot" to tell us. That happens. Would be way easier to see in person...

so, yeah, it can be frustrating, and usenet can degenerate into a flame war, but most of us are here because we like fixing cars and talking about fixing cars and getting ideas on how to fix cars (and own broken cars that need fixing.)

Ray

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That is the second force on the lugs. One is to hold them to the hub, the second is to resist shearing during acceleration and braking. Think about it for a minute.

Lg

Nope, there should be NO shear on the lugs. The braking/acceleration forces should be taken care of by the friction of the wheel against the hub. Lugs will fail fairly quickly if they are loaded in shear.

nate

Should be taken care of by the friction of the wheel against the hub.

Nate, my hubs are smooth as a baby's ass. Like glass. There ain't enough friction between the wheel contact surfact and that hub to stop a 3,800 pound vehicle doing 80 miles/hour.

There are multiple *moments of force* applied to the lugs. During turning at speed, during acceleration and deceleration. Just because the wheel doesn't move relative to the hub doesn't mean that the forces to shear the bolts isn't there.

If you were going to ELIMINATE shear forces on the lug nuts, nate, you would build a hub with keyways in it to accept a wheel with the keys.

Think about it will ya?

Lg That's MY STORY AND I'M STICKING TO IT.

Like if the holes went oval because he said he ran with loose nuts for a while and has already sheared lugs twice....

Mike

86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00 88 Cherokee 235 BFG AT's Canadian Off Road Trips Photos: Non members can still view! Aug./05 (More Off Road album links at bottom of the view page)

A 1/2" UNF bolt torqued to about 60 lb-ft after being lubed with anti-seize will apply a clamping force of something on the order of

10,000 lbs. That should be enough to supply the necessary friction, even considering that the coefficient of friction of steel on steel or aluminum on steel is fairly low. In any case, the lugs are not *designed* to accept any serious shear loads, and they will fail if they are subjected to same.

nate

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I said, that's my story and I'm sticking to it. Your 10,000 lbs of clamping force is creating a more immovable slip differential, but movable it is. There is no keyway. There is only friction. And the friction ALONE is not enough to stop a moving automobile, or propell one forward at high levels of acceleration.

I take it you slept through most of physics class. If you think that lug nuts are just there *to hold the wheels on so they don't fall off.*

You have 5 of these, a cross section of each being 1.95 inches of round stock. For each wheel. That's it. Along with the friction of the tire itself against the rim of the wheel. That's what keeps the wheels from falling off AND keeps them from standing still while the hubs spin against them.

2 inches of bar stock steel per wheel, times 4 wheels, = 1 each 8 inch diameter billet of stock round steel bar that stands between you and DEATH when you hit the brakes.

There are MULTIPLE things that keep your wheels affixed. And it isn't JUST, as you claim, the friction between the aluminum and the steel hub.

If friction were important, then why the hell use a polished hub? Why not a rippled one to interlock with a rippled mating surface on the wheel?

I'm not going to argue beyond the point of saying if you think that there are no shear forces during acceleration and braking, you are mistaken. And I don't believe that these shear forces are completely explained away by the friction of the tightned wheel against the hub. I believe that the lug bolts take some of the force. Believe what you like.

Lg

There's a lot of things that don't seem intuitive and yet prove out when you do the math and/or perform a test. This is why we have engineers, otherwise you could just design crap on the back of a cocktail napkin and it would always work. In any case, I'm inclined to believe what I was told by several professors than some guy on Usenet. The fact remains that bolts in general are designed to be loaded only in tension, and that lugs are no different. Reversing and/or shear loads will make them fail much, much quicker than they otherwise would. (in an ideal world, they would never fail, being steel.)

nate

*Some guy on usenet* has this question for you nate:

If you attach a wall bookshelf with angle brackets, and put books on top of the shelf, where are the forces on the screws holding the angle brackets to the wall.

I know that is a question. You can put the question mark at the end of it if you like.

Lg

What happened to "I'm not going to argue beyond the point...."?