Front hub studs breaking off

[Kynot62]

Eric

I am at a bit of a loss as I have never broken a wheel stud. And Cruiserdrew is right about this not being a common problem. Unfortunately it is a common problem for your rig and needs a solution.

One train of thought- I know it would be hard to tell but could the problem come from long ago when some idiot got crazy with an impact gun, over stressed the studs and they are each failing in turn as time goes by? Or is it the same stud failing over and over? Is there a time when this started, after a brake job possibly or has it always done it? Both sides or just one?

It is possible that the holes for the studs in the wheel hub itself have been drilled at an angle so every time a stud is replaced it goes in at a slight angle, the wheel goes on, gets tightened, trys to straighten the stud and possibly weakens it, and eventually fails.

Are the holes in the wheel hub slightly oversized so the studs aren't held in place as well as they should be?

I would think the brake rotors have been replaced at least once probably more. The studs press on from the back (at least in my 62 they do, are 60's the same?), its possible the wheel hub was damaged along the way.

I wouldn't change the entire hub just yet but it's worth looking at. (New hubs aren't cheap) I would say bring your rig by but I am North of Seattle so thats not an option. Finding a good cruiser mechanic that you trust will be high on your list.

Keep me posted

Tony

 

[GAS-A-LOT!]

Qu

Ahhhight!


Welcome!

I think the over stress is right. I've have one or two replaced on my 80. Because of them air gun thingys... LOL.


One question though. Are the new ones breaking ? or is it just the old ones? You might end up with a new set by the end of the year....(Gas-a-lot gets boo-ed off the stage)

Seriously though... the torque is different between the steel and aluminum OEM's... and I've seen them do no adjustment when working on both. So that kind of tells me that I need to start carrying a couple of OEM studs for when I travel, or need one down the road.

Don't know if any help...

Side note: I hope fellow mudders don't start buying flame throwers for use on newbs like them other forums.... Reason why I don't go on them other forums... I like it here...

 

[ntsqd]

I must say that from the original posting that I wasn't sure if the OP was referring to the studs that hold the locking hub on, or the studs that hold the wheel on. So I delayed responding pending further info. I see we've got that covered now.

As others have said, the ONLY way to install new studs is to push them in from the back. Pulling them in is a no-no and gives the results that you are experiencing. If it is only the old studs that are breaking then I too am thinking over-torqued at some time in the past.
Otherwise you've got something odd going on that it will probably take an experienced eye (or several) to spot.

My Rule: The tool that I will use to remove the lug nuts in the field somewhere is the ONLY tool that removes or tightens them. Nothing worse than a flat on a wheel that had it's lug nuts run on with an air gun and that are tighter than any normal wrench is going to be able to remove.

I'm in the same camp re: Anti-Sieze. I can not imagine a valid argument against using it, but I've experienced the worst that can happen from not using it - and that's not fun.

Depending on where you are in LA, you may be close by. I have a press and can push in a set of new studs if you can bring up the loose parts. My place looks like Cal Worthington's back lot at the moment, so no place to pull it apart here.

 

[lehiguy]

That seems like on odd problem, I have 350k on mine and I never broke one. And honestly, I'm a bit bit wreckless with the impact gun. I think starting from scratch with all-new studds would be the best approach. You might as well do new rotors while you're at it since it's the same process. One overkill idea might be to enlarge the holes in the actuall hub and use a larger, domestic wheel studd. This requires drilling the holes in your wheels to 5/8" inch, not hard to do, its only an increase of 1/16" or so. I had to do that to get my wheels to fit on my Chevy rear axle. Then the lug nuts are also larger, so be mindfull that you would need the proper tools to remove then on the trail.

 

[daviesl]

heat?

maybe the combo of over torquing and heat due to high rotor temp caused the breakages? If your rotors are rubbing at all alot of heat could build up in the area weakening the studs. Maybe you drive with the brakes on? High fuel consumption problems? Maybe your rear brakes aren't adjusted properly and all the energy is being disipated by the front rotors causing excessive overheating? Make sure your tires are balanced too. What size tires are you riding on?

 

[IH8Wood]

Somethings not right. My suspicion is the hub. If it was me, I'd pick the wheel that has broken/rebroken the most wheel studs and pull off the hub housing. Pound out the studs and carefully examine the area where they're pressed in.

 

[Grady]

FWIW, I'm guessing there was no press, except maybe on the full set mentioned. The air wrench pulled the studs through, deformed the studs, and after a few hard corners they snapped off. Not to bring up the pictures again, but a good pic of a freshly broken stud could tell if it was a shear or tension break.

 

[grant5127]

All this talk about their own personal torque.....

someone even mentioned differences between types of wheels....

but I see no numbers.......

so what values are all you cats using??

I have the FSM recommended "WHEEL NUT" torque.....wanna know?... seems kinda high in my way of thinking.........

 

[IH8Wood]

All this talk about their own personal torque.....

someone even mentioned differences between types of wheels....

but I see no numbers.......

so what values are all you cats using??

I have the FSM recommended "WHEEL NUT" torque.....wanna know?... seems kinda high in my way of thinking.........

The user manual (not fsm) says 65 - 87 ft lbs

 

[cruiser88]

jebus......90

 

[GLTHFJ60]

As tight as I feel they should be, using a regular tire iron. I've rotated my tires once, 10k ago and have no problems yet.

 

[lovetoski]

I have broken two studs. Brand-new OEM, with brand-new OEM nuts. I know why they broke. Based in part on advice from this forum, I put anti-sieze on the studs. Turns out, if you get the anti-sieze on the face of the nut, where it contacts the wheel, it's really easy to break a stud. The torque is developed in large part by the friction between the face of the nut, and the corresponding beveled recess in the wheel. Anti-sieze significantly reduces the friction, thus enabling you to turn the nut down so far on the stud that the stud stretches and breaks.

Oh, I torque my nuts to 90 ft lbs.

The nut/wheel interface must be clean.

If you have had a couple of studs break, perhaps they were previously stretched. I would replace all the studs and nuts. Anti-sieze on the threads is fine, but not very much, and keep it off the face of the nut.

 

[grant5127]

Hookes Law Constant:

States that their research showed an increase in the tensile stress in the bolt by a factor of more than FIVE as a result of lubricating the threads with anti siege compared to clean dry threads, using the same tightening torque in both cases.........

 

[donny paradise]

The factory recommended anti-seize on my cousins Porsche
Discount Tire did a over-dose when he had new casings installed and the crap flung all over his s***

 

[ntsqd]

It never would have occurred to me to put anti-seize on the face of a lug nut, nor would I have allowed it to remain there had some gotten on it/them. The whole point of the conic seat, I believe, is to form a locking fastener and to center the wheel on the hub. Anti-seize in that interface would defeat the locking feature.

------------------

I'm having a hard time believing 5 times change in the Tensile Loading of a Bolt. Since the page (linked below) doesn't do metric I used a 1/2-20 as a sample calculation. These are the suggested torque values to create a given tensile loading of the bolt. There is not a factor of 5 variance in the suggested torque values as there should be if the 5X number is correct.


Condition Required Torque
lb-ft N-m
Dry and clean: 110 150
Zine-plated: 110 150
Cadmium-plated: 90 120
Light lubricated: 100 140
Well lubricated: 84 110

So from dry to well lubricated wants a reduction of 26 ft-lbs. To achieve that 5X the dry torque would have to have been 240 ft-lbs.

eFunda: Estimanation of Torque Required to Fasten Bolts



The formula to calculate a suggested torque for a given bolt loading looks like this:
T = P * K * D
Where:
P = Bolt Load [75% of the yield strength of the bolt * it's Tensile Stress Area (TSA)]
D = Nominal Bolt Diameter
K = "Nut Factor" (unitless), accounts for differences in friction (though NOT a Cf!) and other intangables

TSA:
Shank of bolt: A = .7854(D^2)
Threaded Section: A = .7854(D-.9382P)^2
(D = Diameter; P = Pitch, in this case the metric thread pitch)

Values for K:
Moly based lube: .10-.18
Nickel based lube: .10-.12
Copper based lube: .08-.23
Cadmium plated: .11-.33
Zinc plated: .08-.53
Black Oxide: .11-.28
Mild alloy bare steel on bare steel: .16-.27

Because these values for K are not exact that the torque values are suggestions. Each unique combination of nut & bolt or stud will have a unique value for K.

 

[Mace]

Hookes Law Constant:

States that their research showed an increase in the tensile stress in the bolt by a factor of more than FIVE as a result of lubricating the threads with anti siege compared to clean dry threads, using the same tightening torque in both cases.........

You wanna provide a link to this study? Who is "their"?

I have always used antisieze on my lug studs.. But not on the face of the conical nut...

 

[lehiguy]

As much as I don't want to be the jerk who says it's "user error," that's all that I can honestly come up with. I could go to the garage right now, put the factory tools on the lugs and break them off by allowing the turning force to misdirect into a sideways force. There, I said it.

 

[lovetoski]

It never would have occurred to me to put anti-seize on the face of a lug nut, nor would I have allowed it to remain there had some gotten on it/them. ...

Just to be clear - I didn't put anti-sieze on the face of the nut intentionally. I did it through ignorance (some could say stupidity...). I put it on the threads, prolly more than was necessary, and some got on the nut. Sloppy, perhaps. Didn't know it would be a problem. Some things you learn by fxxxing up.

But this is about the original poster, who's having multiple stud failures...based on my own experience, I would guess there is a scenario where (over the course of 280,000 miles) the nut/wheel interface had less friction than it should, and the studs got stretched.

Eventually they will fail. Replace them. Drive on.

 

[tonyota]

Through all the "your being mean" & Technical jargon & antifreeze on lug studs & Just how fat was the guy leaning on the torque wrench... I can't remember if these are stock steel rims or aluminum rims. I do know that the mating surface of both the rim & hub on aluminum rims must be free of corrosion each time the wheels are installed, or this can cause looseness, just enough to cause a wheel to move a bit & maybe , just maybe break a stud. Also factory Toyota Aluminum wheels require a special lug nut for proper seating.. I just wanted to spout out that info. & say ...take a little ribbing from the guys, it's no different then if we were all in the garage together havin fun. And I also thought initially, that we were going to be talking about the locking hub studs. Ok, I'm done, I probably didn't help, I may be an a**, would anyone like to belittle me for fun? I kinda like it.

 

[Joe_E]

You wanna provide a link to this study? Who is "their"?

I have always used antisieze on my lug studs.. But not on the face of the conical nut...

I'm with you Mace. I have used never seize on every wheel stud on every vehicle I've ever had and never had an issue with breaking a stud nor have I ever lost a wheel .
I've never torqued a wheel either. Just a good ol 1/2" breaker bar .