Driver Side Hub/Rotor spit out lug nuts (or: I hate mag wheels)

'92 XJ, now 6" lift, 33s, aluminum AR Outlaw II mag wheels. Lug nuts are the type that go into the holes on the wheel and use washers, instead of sitting on the wheel. I hate them. My wheel bearings are about a year old with very little wheeling.

So last Saturday a friend swapped out my 2" adjustable shackles for shorter boomerang shackles. Swap was done & the ACOS dialed down to match. I watched him impact the lug nuts back on & I took off thru his neighborhood. Shortly thereafter I felt a thud, but I just assumed it was the shackle hitting the exhaust or something. Then another thud. Then the XJ started to limp, listing towards 1 side. I immediately pulled over, thinking I had snapped a shackle bolt or something, only to discover the driver front wheel was being held on by 1 lug nut (de ja vu ...).

Long story short, I actually was able to account for all 5 lug nuts - one had snapped in 2, one was still on the hub, and I found the other 3 by walking back down the road. After the repair on the way home the XJ seemed wobbly, had a kind of vibration so I took it easy. We hadn't seen any visible signes of damage on the rotor or hub so I'm wondering what the problem might be. Any one have any ideas?

did he only use the gun? you can over tighten lugs that way.

only use the impact gun to snug the lugs then torque them down with a torque wrench.

I never let shops use an impact wrench on my lugs. They will give you a BS story about how the tool will flex and not over impact the lugs...it's BS. I used my torque wrench to loosen a set after they were run down with and impact and it took over a hundred pounds of torque to get the lugs to break loose. A friend of mine spent several months in the hospital with a severe head injury because his lugs sheared like yours and he rolled his Ford F-150. I tell them to torque them with a wrench to specs and then I watch. If they don't like it they don't get my busibess. Either way I still double check the work when I get home by retorquing the lugs.

Mighty.Mighty_XJ said:

aluminum AR Outlaw II mag wheels. Lug nuts are the type that go into the holes on the wheel and use washers, instead of sitting on the wheel.

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:dunno: My Outlaw II's used regular stock style acorn nuts. Are the bolt holes not chamfered out to accept an acorn nut? If they are just flat, you could probably just add the chamfer with the correct drill bit and go back to using stock style nuts.

My bet is that you bent a lug stud or two, which is why it's vibrating funny and stuff now.

I also never use an impact wrench to put lug nuts back on, but I don't use a torque wrench either... I tighten em down to "good n tight" and I've never had one work loose, come off, or seize on, so I think I'm doing OK.

Gonepostal - torque to get the nuts to move after they stop turning will be much higher than torque while the nut is still turning, which explains those readings (static vs dynamic coefficients of friction.) That said, I am likely setting mine to ~120 to 140 based on the way it felt when I torqued to 100 with a torque wrench and then set them my normal way after (I was curious how much I was adding.) At some point I'll probably find a torque wrench with a shorter handle so I can find out how much torque I actually set mine to.

I do appreciate all the comments, but only Ken has suggested or taken a guess as to my actual question: what could be causing the vibes? I need for this XJ to be fully streetable in the winter.

foxwar71 said:

:dunno: My Outlaw II's used regular stock style acorn nuts. Are the bolt holes not chamfered out to accept an acorn nut? If they are just flat, you could probably just add the chamfer with the correct drill bit and go back to using stock style nuts.

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My solution to this is currently sitting in my heater shed - another set of 4 wheels, then I'll sell the ones I have. (It's just too cold to paint them black right now since I just got 'em, so they'll sit until the temps improve.)
I understand your logic, but I have no idea how to do what you're suggesting. With these wheels using standard lug nuts, there's not enough exposed threads for them to grab. And the hole around the bolts is wider than normal since they're designed for the mag lugs to be inserted.

kastein said:

My bet is that you bent a lug stud or two, which is why it's vibrating funny and stuff now.

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I think you could be on to something there, Ken. I guess I'll prolly have all the bolts changed then. I'd hate to have to replace the whole wheel bearing so soon. Hope it's as simple as this ...
Thx!

It's pretty easy if you want to give it a try yourself - to check if they're bent:
* jack end of axle up, remove wheel
* remove 2x 12mm bolts holding brake caliper on, pry brake caliper off (I find the handle of a 3/8" ratchet under the caliper where it goes across the edge of the rotor makes this easy, make sure you're prying at the end that doesn't have the caliper retainer notches in it)
* remove rotor (unless it's heavily rusted on, all you have to do is grab it and pull)
* spin unit bearing by hand while sighting down the profile of the lug studs, see if any are bent

If they're bent, buy new ones (a couple bucks each at NAPA) and pound the old ones out with a hand sledge. Buy a big stack of 1/2" grade 8 washers (probably 8 or so will be fine), insert the new lug stud from behind the unit bearing flange, load it up with washers, and tighten a lug down till it pulls the splined portion of the lug stud into the flange. You might have to take the lug back off and add more washers once or twice if your lugs aren't open-ended.

Then reassemble everything and you're good to go!

Aside from bent lug studs, all I can think of that would cause this is a warped brake rotor, bent wheel, or bent unit bearing wheel flange, which is unlikely.

Are your studs long enough for the wheels you are using?

Did you carefully check the wheel itself--it could have "egged" the holes.

It sounds like you have hub centric wheels installed and what you need is lug centric wheels. The wheel has room to move even if the lugs are tight because the bolt holes in the rims are oval shaped. You need to get some lug centric wheels.

kastein said:

My Gonepostal - torque to get the nuts to move after they stop turning will be much higher than torque while the nut is still turning, which explains those readings (static vs dynamic coefficients of friction.) That said, I am likely setting mine to ~120 to 140 based on the way it felt when I torqued to 100 with a torque wrench and then set them my normal way after (I was curious how much I was adding.) At some point I'll probably find a torque wrench with a shorter handle so I can find out how much torque I actually set mine to.

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Thanks but I was already aware of this...guess I took physics as well. After a vacation nightmare created by a tire shop running my lugs down with an impact, I got picky. The listed torque for the XJ lug is 85-115 ft lbs. I torque mine to 90 ft lbs taking into account that I generally go around the pattern twice to assure they are pulled down square and true. I have always been able to change my flats and have NEVER had a rim work loose. You could call it the anal tendencies created by working on antique cars from 1920s and 1930s for over thirty years with my collector father.

Both shops I've worked in, we use torque sticks - never had a problem yet. On a 4 lug bolt pattern I'll use a torque wrench just to be sure but only rarely will I find anything other than the stick was rated at.
My old man claims that even a torque stick is overkill, he's been hot rodding for 40 years and putting lugs on with his 1/2" Ingersol and a socket, never had any problems.
To each their own, but if you have the strength to break loose the bolts I don't think you can hurt much using an impact wrench unless you go totally buck wild with it.
To the OP... The rim may have distorted as it was rolling with decreasing security / less even clamping. I would also look for bent lugs, as others have said, and spin the hub while looking in profile and see if it is spinning true.

jeeperjohn said:

It sounds like you have hub centric wheels installed and what you need is lug centric wheels. The wheel has room to move even if the lugs are tight because the bolt holes in the rims are oval shaped. You need to get some lug centric wheels.

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This is my vote. Are they hubcentric wheels? They could very easily cause a vibration if they are hub centric on a lug centric hub. Although, I would expect you to have a vibration problem all along if this were the case, unless you were lucky enough to put them all on perfectly before.

you should always put a torque wrench on the lugs as a last step. It is not just about sufficient torque, but also a reasonable consistency. If a lug is significantly looser than those around it, it can work loose. Despite the success stories of people that have never lost a tire and only ever used an impact, I would not take the chance. party1: