crazy story for all you sc'ers

two1six

Registered User
i have a 93 sc. so while driving down the road i feel some vibration from the rear. i think to myself, oh great either a lead weight fell off or time for a new wheel bearing. then again i just had new tires put on. so all signs pointed to wheel bearing. so i take off the lug nut cover to investigate. come to find out i have only two out of the five lugs holding the wheel on. the other three broke clean off. :( i guess these cars really are torque monsters!!!!! :D
 
If you just had new tires put on I'd go back there and give someone a piece of my mind....there is no way you get enough traction with street tires to do that---they had to have come slightly loose. If doesn't take long for a wobbling wheel to break some studs............Dan
 
If you just had new tires put on I'd go back there and give someone a piece of my mind....there is no way you get enough traction with street tires to do that---they had to have come slightly loose. If doesn't take long for a wobbling wheel to break some studs............Dan

I think he meant the studs broke not that the lugs backed off of em, could be wrong though
 
well i did the tires myself, with the help of a buddy, a shop, and a six pack. so they could have just been stretched studs. but they broke clean off.
 
I think he meant the studs broke not that the lugs backed off of em, could be wrong though

But three studs don't just break because they're feeling tired that day, and especially not because someone launches hard on street tires. They probably broke because they (and the other two) weren't torqued enough at the tire place.

First thing you gotta do: check the other three wheels!
 
I think he meant the studs broke not that the lugs backed off of em, could be wrong though
Trust me...if lugs back off just a thread or two and the wheels start to wobble the studs WILL break with the lugs still on them. As a matter of a fact the studs will break quicker with the nuts ons and just a bit loose. Metal fatigue can set in and they break in as little as a half mile....as someone else said---first thing to do is check the lugs on the other wheels NOW.....Dan
 
I would tend to agree with old coot;) Most of the big dogs run over 400 rwtq with stickey tires at the track and never have problems with broken studs. With street tires and lack of real traction no SC going to break off studs, just my 2 cents

Ken
 
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oh well it happens. just glad it didnt come off. but then again who knows. one could have broke off. then i didnt notice it, causing another to break, then so on and so on. plus i should probably not be driving this in the winter. because the car is in pretty damn good condition for what i payed. i practically stole this one! but its my only ride:(
 
oh well it happens. just glad it didnt come off. but then again who knows. one could have broke off. then i didnt notice it, causing another to break, then so on and so on. plus i should probably not be driving this in the winter. because the car is in pretty damn good condition for what i payed. i practically stole this one! but its my only ride:(

Were you using an impact wrench to install the lugnuts when putting on the new tires ? They should be torqued to 100 ft lbs.

David
 
i have a 93 sc. so while driving down the road i feel some vibration from the rear. i think to myself, oh great either a lead weight fell off or time for a new wheel bearing. then again i just had new tires put on. so all signs pointed to wheel bearing. so i take off the lug nut cover to investigate. come to find out i have only two out of the five lugs holding the wheel on. the other three broke clean off. :( i guess these cars really are torque monsters!!!!! :D

NOPE, the car is not the torque monster in this scenario!
The culprit is whoever put the wheels on!
Did not ensure the lugnuts were torqued down.
A million scenarios as to how or why they were not torqued but bottom line is... lugnuts were loose.
Check all other wheels NOW.
Ensure the rim is seated flat against the brake rotor. hand tighten all 5 ensuring the lugnut is seated IN the rim properly, then torque them down in sequence.

IF you had the wheels done at a shop... I WOULD BE PISSED!
IF you did them at home... bow your head and chock one up to an OOPS! I'LL NEVER DO THAT AGAIN!

It happens! I forgot to pump the brakes once on a car I did full brake job and other things over a few day period. Brakes were done day 1, other stuff took a couple days... day 4, hop in car, start it up, put in reverse, go to stop car as it is coming out the garage and OH CHIT NO BRAKES! PUMP PUMP PUMP! thankfully I got it pumped up before I went out in to the street! OOPS! I'LL NEVER DO THAT AGAIN!
I was 14 at the time. NEVER DONE IT AGAIN! Come close but never actually did it again.
 
Torque Sticks baby!!! Makes life easier!

I have a few sets of those, you actually have to use them at some of the dealerships and shops around here. However I always go one step below what I need the final torque at, then finish them off with an actual torque wrench.
 
i guess i am going to take a page out of regul8r's book and bow my head and chock one up to the oops column. i guess it was a freak accident. i did check the other wheels and they were all torque'd to spec. im just glad my wheel didnt come off. i have seen that happen before. this guy was driving in his jeep on a main road. he stopped and the wheel kept going.
 
Maybe it's time for a lesson in bolt strength, lug torque, and wheel studs.

First of all, lug torque as specified by the manufacturer is a somewhat nebulous figure. It is frankly impossible to specify a torque for wheel nuts that will be consistent and applicable across the board for every application.

1) Factory specs assume new condition threads, without lubrication, on both the nut and stud. Any corrosion or contamination of the surface will increase the torque requirement, any lubrication will reduce the torque requirement.

2) Remember, tightness is not relevant. What is relevant is the stretch on the stud. The 100ftlb recommendation is only a guess based on a new stud/nut combination. It is possible to overstretch a stud with 90ftlbs if you use some lubricant on the threads. It is possible to under torque at 110lbs if the threads are damaged.

3) Stud stretch. An experienced hand will know when a stud starts to yield. Unfortunately for everyone else this may be hard to recognize. Once a stud has started to yield, it cannot be torqued. Period. It will not hold. You have to replace it. On a car 15yrs old, it is very likely to have fatigued studs.

4) All bolts have a life cycle. They can only be torqued to their proper stretch point so many times. Depending on the quality of the bolt/stud, this cycle is probably in the range of 8-12 times. After that the stud has to be replaced or it is not able to hold it's torque anymore. If you are a person who tends to over torque a bolt, or maybe the previous owner was, then lifespan can be seriously shortened. People who change tires/wheels at the race track should be especially aware of this.

5) Over-tightening of the lugs can ruin your aftermarket wheels, warp rotors, and cause highway speed vibrations.

6) Lubrication on the threads does not cause the lugs to back off. If the stud has and is holding proper tension, it will not back off. Think of all the bolts inside your motor. They are all fully lubricated before assembly, use no locking devices and they simply do not back off. Ever.

7) If a stud was torqued correctly and the nut comes loose then that is a huge red flag - you have fatigued studs! Replace them.

8) Nuts. Nuts don't stretch and so they aren't subject to cycling failure like the studs are, but the threads can become damaged. If the nuts do not go on easily by hand, they should be replaced. If the nuts feel loose when threading on by hand, they should be replaced. If the nuts have galling on the conical face, they should be replaced, but if they have galling on the face (much more common than you think!) then the wheels have also been damaged. Be aware of this. Again, for you track guys, using lug nuts with galled conical faces will damage your other wheels as well.

9) Within reason, no amount of driveline or engine torque will ever shear off any wheel stud. The studs do not carry a significant amount of rotational torque. Instead, the wheel lugs clamp the wheel to the hub and it's the friction of the wheel against the hub that carries the torque load of the driveline/motor.
 
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Good info Dave...

Also, using and extension on your torque wrench will alter the actual torque applied to the lug nuts....
 
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