My lug studs have a finite life

[eljefino]

...and we're near the end. Snapped one off in the front and one in the rear, another in the rear doesn't give me confidence. 95 Saturn, almost 14 years old, maybe more if you count date of manufacture.

I thought I looked cool last winter running without hubcaps with my steel wheels and snow tires, wonder if my open ended lugnuts provided a nice place for salt to hide in the threads.

They sounded really creaky last spring, and the tire iron bounced on break-loose. I can imagine the studs just twisting and untwisting repeatedly. I hand torque and a tire/wheel probably comes off three times a year... snow/summer changeovers plus one "other" bit of maintenance.

I never do any of that fancy stuff like brushing rust off the studs, because the nuts going on go on smooth: The loosening and removal "retaps" the studs enough IMO. (but am rethinking now.)

So I swallowed my pride and after >5 years of doing all my own work I'm going to a mechanic with a torch to "somehow" get my rear brake drums off and fix my stud... and, perhaps, all of them. That drum's been rusted on there for a while, there's no rim to hammer off, it crumbled away, so it'll be good to renew everything in the rear...

 

[soldierman]

If the drum is in need of replacing or is cheap bust it off. If you have a die gringer or an angle grinder cut a line almost through from the hub to the outside edge then a few good whacks and it will crack. When it does it'll slide right off.

 

[Steve S]

You might as well have all of then replaced since they all are old. I lube the studs. Help the CEOs get their millions of dollar pay checks and buy a new car. Be patriotic and get into major debt .

 

[WishIhadatruck]

Originally Posted By: Steve S
...get into major debt .


Isn't that a big part of the reason we're in this economic mess?

If you can't do it yourself I'd have the mechanic replace ALL the studs assuming you plan to keep the car for a while.

 

[labman]

Start lubing the studs. I have for years and never twisted one off or had a lug nut come loose. I used to use motor oil, but now use anti seize. I also apply it to where the brake drum fits the hub.

I do torque to 80 foot pounds rather than the 100-105 specified.

Studs don't get old, just misused. Yes, you may as well replace all the over stressed ones.

 

[George7941]

I use Loctite Threadsealer #567. It lubricates the threads during assembly and disassembly and it sets up like a very mild threadlocker. This prevents lugnuts from working loose and it fills up the gaps amongst the threads of the mated assembly, preventing corrosion.

I also use antiseize on the wheel rim bore which mates with the hub and this prevents drums, rotors from sticking to the hubs.

 

[eljefino]

Lube is one of those never ending discussions. I did lube the stud I replaced last month with WD40 (because it's a terrible lube and might evaporate off) so when I pulled it through by torquing the lugnut the splines at the inner end wouldn't spin and would instead seat properly.

As far as the brake drums, I also antisieze the mating surface but this car has been in service since before I started that practice... so I had a policy of letting sleeping dogs lay. They're waking up.

 

[Ken2]

Quote:
"somehow" get my rear brake drums off
Try loosening the lug nuts, rolling forward, brake, roll back, brake, etc. VERY CAREFULLY to loosen the drum. Don't loosen so much that the holes in the wheel are damaged. Soaking the hub with penetrating oil might help. If you have heat, try heat...a propane torch or electric heat gun might work. Get it hot and see if it loosens...bang it with a board hit with a sledge hammer but don't bend or break anything. Or get it as hot as possible with those moderate heat sources, then cold shock it with a dousing of ice water. That'll get things moving and fracture the rust.

Lubing the lug studs is a big question mark. Lube changes the torque requirement to get equal stretch of the stud, but we don't know how much unless the material of the stud, the type of metal finish, and the lube are factored in.

 

[lyle]

Even NEW studs have a finite life.

4 years ago I rotated the tires on my wifes NEW Taurus, 6000 miles on the clock. I hand-threaded the lug nuts on and firmed them up with my impact wrench and 40ft/lb torque stick. I put the torque wrench on the first nut and started to turn. Normally it's no more than 1/8 to 1/4 turn to get 90ft/lb, but these darn things kept turning. I stopped and tried another nut, same thing. I went to the other 3 and turned them 1/4 turn and stopped. I went to the first one and figured I'd turn it with the torque wrench until it stopped, which it did when the STUD broke. I went to another wheel and darned if I didn't come across the same situation.

I broke 3 studs total and the following Monday had the car at the dealership service department. A writer had the nuts to tell me I was doing something wrong, and I would have to pay for replacing the non-broken studs, but that they would cover the broken ones under warranty. I walked back to my car with a tech in tow, asked him to set a torque wrench to 90ft/lb, and asked him to torque one nut. When he broke THAT one, they replaced all 20 studs under warranty.

I never found out what the deal was, but that has been the only mechanical anomoly on that car ever.

 

[1sttruck]

Wheel studs seem to come from the factory these days with an antiseize coating so I don't worry about using some on all of the vehicles. Initially I use a small amount, brushed on, and typically don't need to apply more for awhile. All of the vehicles get at least a tire change each year for winter tires, and I've not had a stud break yet. I use a breaker bar / speed handle to take the tires off / get them mounted, and finish with a beam type torque wrench.

Properly heat treated steel protected from corrosion, hydrogen embrittlement, etc., has essentially an 'infinite' life provided stresses are kept within limits, meaning that things can and do go wrong.

 

[eljefino]

My new studs are sitting here and they have some sort of oily corrosion protection.

I'm not a rough tough sort but I have to estimate less than the usual 100 ft lbs sheared 12mm worth of mediocre steel.

In a further act of stubbornness one of my brakes locked up (then unlocked by "magic") so screw the mechanic, I'm not leaving my driveway until these drums come off by horse or by force.

 

[XS650]

Originally Posted By: labman
Start lubing the studs. I have for years and never twisted one off or had a lug nut come loose. I used to use motor oil, but now use anti seize. I also apply it to where the brake drum fits the hub.

I do torque to 80 foot pounds rather than the 100-105 specified.

Studs don't get old, just misused. Yes, you may as well replace all the over stressed ones.


That sounds like a good guess for anti-seized studs.

At least your stud tension is consistent. The people not lubing their studs with varying amount of rust on them are under tensioning the studs at factory torque.

 

[eljefino]

Once the "acorn" face of the lugnut starts rubbing its dry mating surface on the wheel, you'd have to take into account that much unlubricated friction in addition to the lube on the threads. Seems like a figure you'd have to "fudge".

 

[Hokiefyd]

From what I understand, using a lubricant on the threads themselves doesn't require much torque adjustment, as far as the specification goes. But if you get the lubricant on the face of the lug nut (the acorn or the washer, depending on type), THAT significantly reduces the friction and requires a torque adjustment.

I've had tires mounted at both Sam's Club and Walmart in the last year, and both of them used the copper colored brush-on anti-seize. They didn't use a lot, and when I took the wheels off to rotate them, the nuts came off real easy. I think I'll start doing the same from now on.

 

[labman]

With my 19'' torque wrench, I can easily hit 100 lbft using the muscles in one arm, and I don't feel the stud twisting. When I feel the stud twisting with both hands on my 17'' breaker bar and lifting with my legs, loosing a dry nut, I figure I am asking to twist off the stud. I decided I was going to lube both the threads and the mating face. 80 lbft has worked well for me on lubricated 12 mm studs. You may need more on bigger ones.

 

[eljefino]

Alright peeps here's how you get a stubborn drum off without a torch. Grind a couple tangents so a little triangle forms, which will fall out. Note the thickness of your new drums and don't grind down any further than necessary, as you won't know the hub/bearing flange metal from drum metal. The drums, being cast iron, will be softer. I barely nicked underneath.

Thanks to a poster above for inspiration, I kind of thought of this plan before but then figured it was insanely crazy.

Lost a stud on the other drum side as well, that's three in the last month. All my snow tires are on now though and she's ready for winter.

 

[Kestas]

Originally Posted By: Jason Adcock
From what I understand, using a lubricant on the threads themselves doesn't require much torque adjustment, as far as the specification goes. But if you get the lubricant on the face of the lug nut (the acorn or the washer, depending on type), THAT significantly reduces the friction and requires a torque adjustment.

Bingo, this is exactly what testing in our lab showed. Studs can handle a considerable amount of overtorque until they neck and fracture. We didn't see stud cracking until antiseize was applied to the nut mount face!

 

[PT1]

Originally Posted By: lyle
Even NEW studs have a finite life.

4 years ago I rotated the tires on my wifes NEW Taurus, 6000 miles on the clock. I hand-threaded the lug nuts on and firmed them up with my impact wrench and 40ft/lb torque stick. I put the torque wrench on the first nut and started to turn. Normally it's no more than 1/8 to 1/4 turn to get 90ft/lb, but these darn things kept turning. I stopped and tried another nut, same thing. I went to the other 3 and turned them 1/4 turn and stopped. I went to the first one and figured I'd turn it with the torque wrench until it stopped, which it did when the STUD broke. I went to another wheel and darned if I didn't come across the same situation.

I broke 3 studs total and the following Monday had the car at the dealership service department. A writer had the nuts to tell me I was doing something wrong, and I would have to pay for replacing the non-broken studs, but that they would cover the broken ones under warranty. I walked back to my car with a tech in tow, asked him to set a torque wrench to 90ft/lb, and asked him to torque one nut. When he broke THAT one, they replaced all 20 studs under warranty.

I never found out what the deal was, but that has been the only mechanical anomoly on that car ever.


Metallurgical failure...you had bad studs from day one...consider yourself lucky you didn't find out on the freeway.

 

[PT1]

Originally Posted By: Kestas
Originally Posted By: Jason Adcock
From what I understand, using a lubricant on the threads themselves doesn't require much torque adjustment, as far as the specification goes. But if you get the lubricant on the face of the lug nut (the acorn or the washer, depending on type), THAT significantly reduces the friction and requires a torque adjustment.

Bingo, this is exactly what testing in our lab showed. Studs can handle a considerable amount of overtorque until they neck and fracture. We didn't see stud cracking until antiseize was applied to the nut mount face!


Anti-seize really should not be used on wheel studs & nuts as it will cause them to stretch beyond their elastic range and fatigue and then prematurely fail. If you are undertorquing to compensate then you are just guessing and can create additional wheel runout that effects ride & control. Manufacturers of studs/nuts recommend no lubricant.

 

[Kestas]

Originally Posted By: PT1
Originally Posted By: Kestas
Originally Posted By: Jason Adcock
From what I understand, using a lubricant on the threads themselves doesn't require much torque adjustment, as far as the specification goes. But if you get the lubricant on the face of the lug nut (the acorn or the washer, depending on type), THAT significantly reduces the friction and requires a torque adjustment.

Bingo, this is exactly what testing in our lab showed. Studs can handle a considerable amount of overtorque until they neck and fracture. We didn't see stud cracking until antiseize was applied to the nut mount face!


Anti-seize really should not be used on wheel studs & nuts as it will cause them to stretch beyond their elastic range and fatigue and then prematurely fail. If you are undertorquing to compensate then you are just guessing and can create additional wheel runout that effects ride & control. Manufacturers of studs/nuts recommend no lubricant.

You don't understand the failure mechanisms of wheel bolts. Wheel bolt fatigue only happens if there is movement in the clamped assembly. You won't get this with overtorque, which only results in necking and maybe single event overload fracture.

Also, manufacturers of truck studs actually recommend TWO DROPS of oil on the studs before installing and torqueing the lug nuts.