Keep breaking lugs - advice for hardened lugs??

[maestromaestro]

Ever since I switched to aftermarket wheels, I keep breaking studs. So far - the overall count is 7, all from the front (the rears are a different set of wheels than the fronts - don't ask). Just found out that I have been driving on 2.5 and 2 lugs (driver and passenger, respectively) for a few days.

I do use hub centric rings, naturally, but there is apparently enough vibration to fatigue the lugs - so, I need to switch to stronger material. People mention ARP studs - but this may be an overkill. Anything more "reasonably" priced? Any thoughts?

 

[WhiteST]

So you're breaking studs while driving and the lugs are falling off? Something major seems wrong here.

 

[92FOX]

I'm interested in seeing the cause of this issue...

 

[maestromaestro]

So you're breaking studs while driving and the lugs are falling off? Something major seems wrong here.

There is no big mystery. I suspect that the hub centric rings aren't very "centric" - this causes vibration and fatigue. And when one of the studs goes, the rest "unzip" as well.

I'm interested in seeing the cause of this issue...

One of the issues is that the stud steel that Ford used is complete crap - it simply not hard/strong enough. Two of the studs fell off.

https://goo.gl/photos/ytQudKn2NyRpwxCs6

The other had a crack and I could twist it off with my had.

https://goo.gl/photos/PedqvXN8YqRdrSTx5

However, the 4th one - survived the removal of the lug nut with an impact driver, and was overloaded ("ductile overload") when I torqued it to 100 lbs-ft. So, it broke off inside the lug nut. Given that this was a "regular" sized nut (not the acorn type), and I did not have any extra (I use these for the racing wheels - Enkei RPF1), I wanted to salvage it.

So, I used a left-thread drill bit and a HAND DRILL (!!!) - and it drilled into the stud with no problem and twisted the broken stud right out. I wouldn't expect that from a properly hardened material.

 

[neeqness]

Was an alignment done after putting the wheels on? If not, it could exacerbate the problem...especially if the alignment was off significantly.

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[maestromaestro]

Was an alignment done after putting the wheels on? If not, it could exacerbate the problem...especially if the alignment was off significantly.

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No, I checked alignment yesterday. Nothing major off - toe was slightly off on the passenger side, 1.8 degrees.

 

[maestromaestro]

So - any thoughts on the stronger studs, anyone?

 

[Quisp]

Ever since I switched to aftermarket wheels, I keep breaking studs. So far - the overall count is 7, all from the front (the rears are a different set of wheels than the fronts - don't ask). Just found out that I have been driving on 2.5 and 2 lugs (driver and passenger, respectively) for a few days.

I do use hub centric rings, naturally, but there is apparently enough vibration to fatigue the lugs - so, I need to switch to stronger material. People mention ARP studs - but this may be an overkill. Anything more "reasonably" priced? Any thoughts?

Overkill as opposed to a wheel coming off ? I would figure out what's wrong before driving any distance. I don't think Ford wheel studs are the problem. I guarantee that vendor sells to other makes.

 

[Sekred]

It sounds like you have a problem. Maybe the rim is moving on the hub and breaking the studs because you have a issue with the centric rings. The studs are not really designed to take lateral load, just clamp the rim to the hub. The spigot in the center of the hub and the fit on the rim should take all the weight of the car.

 

[maestromaestro]

Overkill as opposed to a wheel coming off ? I would figure out what's wrong before driving any distance. I don't think Ford wheel studs are the problem. I guarantee that vendor sells to other makes.

The Ford studs are a problem in so far as they can't resist the added amount of vibration. Clearly, not an issue with stock wheels - but, because the hub centric rings that I used are not doing their job, the studs fatigue and crack. A harder steel won't.

 

[maestromaestro]

It sounds like you have a problem. Maybe the rim is moving on the hub and breaking the studs because you have a issue with the centric rings. The studs are not really designed to take lateral load, just clamp the rim to the hub. The spigot in the center of the hub and the fit on the rim should take all the weight of the car.

I believe that the rings are the source of the problem. There is no lateral load; it is a cantilever beam situation, with the threads acting as "stress risers". Added vibration (stress) causes the number of cycles to exceed the fatigue limit on the S-N curve, if you'd like to get technical about it.

 

[awwwww_shift]

I would question wheel torque(over or under torque), the amount of times the studs have been torqued, and the method to which they have been torqued.
While possible, I would venture a guess against that the manufacturing of the studs themselves would be in question. I've seen a lot of stud failures due to over/under torquing of the wheels, or failure due to studs stretching over a period of time/use.

How much are these wheels being changed? How are the lugnuts being torqued? What torque setting are you using?

Not trying to place blame, just trying to understand the situation before diagnosing.

 

[maestromaestro]

I would question wheel torque(over or under torque), the amount of times the studs have been torqued, and the method to which they have been torqued.
While possible, I would venture a guess against that the manufacturing of the studs themselves would be in question. I've seen a lot of stud failures due to over/under torquing of the wheels, or failure due to studs stretching over a period of time/use.

How much are these wheels being changed? How are the lugnuts being torqued? What torque setting are you using?

Not trying to place blame, just trying to understand the situation before diagnosing.

Well, torque is not an issue here. I am using Amrstrong or Tekton torque wrenches; torquing to spec of 100 lbs-ft. The number of torquing events should not play a role in here, as this would be a low-cycle load. On a track, I check the torque after every session. Given the evidence, it is clear to me that the root cause of failure is metal fatigue - the number of cycles exceeded this steel limit. For instance, on one side, I had replaced 2 studs a few weeks back - and yesterday, I found that one of the two "old" ones had an almost thru-thickness crack (broke with my hand - see a pic in earlier post) and the last one broke off upon torquing after I put the wheel back.

Having said this, I will reiterate that I believe that Ford is using cheap steel for the studs. And, you may be right - it is not only the issue of heat treatment, but how dirty the steel may be (inclusions-wise), but I am not inclined to do metallography on the studs.

 

[Xaendeau]

100 ft-lbs is the torque spec? I've just torqued it down by hand to like 70 +/- 20. Cons with running it around 70 ft-lbs? Maybe the steel is too weak for the standard specs.

Granted as soon as I had the money I switched to lightweight 14.4 lb, 15" Sparco rims. Tires are much cheaper, and I don't have to worry about bending rims when I go off road.

 

[maestromaestro]

100 ft-lbs is the torque spec? I've just torqued it down by hand to like 70 +/- 20. Cons with running it around 70 ft-lbs? Maybe the steel is too weak for the standard specs.

Granted as soon as I had the money I switched to lightweight 14.4 lb, 15" Sparco rims. Tires are much cheaper, and I don't have to worry about bending rims when I go off road.

70 +/-20 is a heck of a lot of a "window". Invest in a torque wrench. "Cons" are simple - the bolting force is insufficient, and you are asking for vibration (and that's what caused my issues) and, potentially, the lug nuts would just work themselves off.

 

[OffTheWall503]

I don't think anyone is asking the right questions. What kind of wheels are on the front and what type of lugnuts are you using?

Also, you are supposed to check the torque of the lug nuts after 100 miles or so of driving after installing new wheels/nuts.

 

[maestromaestro]

I don't think anyone is asking the right questions. What kind of wheels are on the front and what type of lugnuts are you using?

Also, you are supposed to check the torque of the lug nuts after 100 miles or so of driving when installing new wheels/nuts.

Well, I do check the torque often enough - not an issue. The wheels on the front are Focal 421B X - 16x7, 4x100, a bit on the heavy side (20 lbs). The lug nuts are acorn type, aluminum (Gorilla brand). Why?

 

[OffTheWall503]

Sounds right, but confirm to double check.

 

[maestromaestro]

Sounds right, but confirm to double check.

PM sent - but never mind. Did not look closely at the chart - it is obviously a general guide.

 

[Hijinx]

Another question to ask... When is the last time your torque wrenches were calibrated? Either your torque wrenches are out of spec or you're using the wrong nuts.

I've NEVER heard of anyone breaking studs.


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