I know this has been posted numerous times, where someone over tightens a lug-nut and snap goes the stud (I did that on my last fiero). But this time, its different. Today I noticed an odd sound coming from the rear driver side wheel, kind of like a flat tire, but alittle more klanky. I normally have the radio blasting so this could have been like that for a couple of days but luckily i had it off today and noticed. So I got home tonight, jacked the car up, and pulled off the lugnut cover (I have after market rims with a pop out center to access lugs). I went to touch one lug nut and it fell off with a piece of stud which had snapped off still in it. Two others did the same thing, so now that hub is down to two studs. Needless to say, Im guessing the car is not safe to drive like this :-/

Im wondering what could cause three studs to snap off like that, the wheel hasn't been off for at least two months when I changed the caliper, and I tightened it down pretty tight, but not so tight that id never get them off again. My dad says he thinks they were too loose as thats what would cause this. What do you think?

So since this is my daily driver, I need to get it back up and running as soon as possible. I took the caliper and rotor off so I could get to the hub, but how does one go about replacing studs? Should I take the whole hub off and replace it or somehow put new studs in? I have a parts car so I could just use one of the hubs from it, how hard is it to remove?

quote Originally posted by jasedude: I tightened it down pretty tight, but not so tight that id never get them off again. My dad says he thinks they were too loose as thats what would cause this. What do you think?

I'm thinking you need a torque wrench!

Yep. I'm willing to bet that your lugs were too loose across the board and gradually stressed the studs out from being pressed and pulled by the wheel, thus they snapped. You mentioned you have aftermarket wheels. What kind of bolt holes do they have and do you have the correct lug nuts for them? (i.e., are they bowl shaped and do you have "tapered" lugs?)

Never go off of "they feel tight" or "good enough to run." When you install a wheel - especially with an aftermarket wheel - properly torque the lugs and immediately within driving 50-100 re-check torque settings. Invest in a proper torque wrench so you can torque the lugs to their specified settings for whatever wheels you have. You especially have to be careful with aftermarket or alluminum wheels because they may feel ridiculously tight, but actually be nowhere near torque specs.

[This message has been edited by Fiero84Freak (edited 12-14-2011).]

Although this usually just contributes to a wheel wobble, not broken studs, are your aftermarket wheels hub-centric or is the center hub larger than stock so all of your vehicle weight is actually on the studs rather than the center hub?

The studs broke after the lugs loosened which allows a shearing force to be applied to them every time you accelerate not to mention the abnormal forces applied to them from the wheel being loose whenever you turn. As for the time it took since the wheel was last removed that's not unusual as it takes enough driving to work improperly torqued lugs loose and if you are using wheels that require a centric ring without one it doesn't help matters.

Years ago I had this happen to me on a different kind of car. Western auto installed some tires and apparently didn't tighten the lugs enough, it took about 2000 miles for the wheel to come off as I was on my way back to Florida from Kansas.

To answer your question about replacement, replacing the studs with the hub on or off the car depends on what year Fiero you have and whether it's the front or rear. If your car is an 88 you should be able to replace the studs without removing the hub for both front and rear. If you own an 84-87 I'm pretty sure you'll have to pull the rotor/hub to replace the studs if it is the front. On an 84-87 you should not have to remove the hub to replace the studs on the rear.

Replacement is fairly straightforward. Purchase new studs from your local auto parts store. If you use the search function here I'm sure you can locate some part numbers. I would recommend that you replace all five studs, as the two that are not broken could very well be near the end of their functional life. To remove the studs just use a large diameter pin punch (basically a round chisel) and a big heavy hammer to drive them out. To install the new ones take a stud to a harware store and find a large nut that is larger diameter than the stud. You should be able to freely pass the stud through the hole in the nut. To install you will likely have to rotate the hub to a position where you can insert the stud through the hole in the hub flange from the backside of the flange. To seat the stud into the flange, slide the large nut over the stud and then thread a lug nut onto the new stud. Here's a tip - when you go to buy the new studs, also purchase a lug nut that is open on both sides so that the stud can pass through the lug nut (like the original nuts that came on the Fiero). So now you have the stud started into one of the holes on the hub flange, the oversized nut on the stud, and a lug nut threaded onto the new stud. As you tighten up the lug nut, the oversized nut will bottom out on the hub flange and then you need to tighten the lug nut until you have pulled the shoulder of the lug stud into the hub flange. Make sure you tighten it until it seats on the back side of the hub flange. To do this you will either need a powerful impact driver, or a long breaker bar (24" should do it). Most lug wrenches are not long enough for this task, you need a long breaker bar to apply enough torque to pull the new stud into position.

[This message has been edited by lateFormula (edited 12-15-2011).]

quote Originally posted by lateFormula: To remove the studs just use a large diameter pin punch (basically a round chisel) and a big heavy hammer to drive them out.

Bad idea. In fact, pounding on the hub flanges with a hammer is always a bad idea. The proper (and easy) way to do it is with a big C-clamp and a deep socket big enough to clear the head of the stud. The GM/Helm factory shop manual has full instructions on the right way to do this.

I do agree: While you're at it, replace all five studs. You don't know the condition of the remaining two, and you can't tell just by looking.

quote Originally posted by jasedude: Im wondering what could cause three studs to snap off like that,

1) Overtightening, including over-enthusiastic use of an impact wrench.

2) Undertightening, as has already been mentioned.

3) Lack of proper centering rings on your aftermarket wheels.

I also agree with Patrick, you need to buy and use a torque wrench. You can buy one for less than $20 at places like Harbor Freight ... not the best, but far better than the "armstrong method."

[This message has been edited by Marvin McInnis (edited 12-16-2011).]

Torque wrench. Way to many people over tighten them. Tire shops use there air guns and 250 pnd compressors to put them on all the time. I learned now to take wheels off and drop them to get tires mounted. Ive got a car coming in soon that shop put wheel on and 4 of 5 studs broke off on their way home and the wheel lodged in the rear fender. I cant count the number of wheels ive had to use a 4 foot pipe on a wrench to get the lugs off. I had a brake job done on a minivan and went to take off the 'service wheels' and put on my nice ones when I got it home. All the studs on every wheel except one stud broke off because they torgued them down so tight, they cross threaded at the bottom. They had to send a guy here to replace all the studs since i couldnt move it.

I keep a 10/12 inch long lug wrench in each of my cars and never tighten a lug tighter than I can get it with that wrench. You dont want your gf to have a flat tire at 2am, 20 miles out in the country with a wheel she cant get off. Cone lugs dont need much tighter than like one turn past hand stop. Shops do same thing with oil filters. Hand tite is all they need. How many of you have had to beat one off with a sledge hammer and chisel.

1 thing I haven't seen mentioned is that there are two types of lug nuts, straight and round taper. Make sure you are using the right type for your wheels as this can contribute to them backing off. Typically steel wheels use round and AL use straight taper.


Also, the use of free floating wheel spacers (ones that don't bolt into the flange) vastly increase the shear force due to the extra torque of the wheel spacer thickness. Doesn't sound like you are using them though.


Chay

quote Originally posted by Slowbuild: ... there are two types of lug nuts, straight and round taper.

There are actually three types that I know of: flat, conical taper (standard on GM cars), and spherical taper. You are correct that you MUST use the correct type specified for the wheels you have mounted ... which is not necessarily the type originally used by the vehicle manufacturer.

[This message has been edited by Marvin McInnis (edited 12-16-2011).]

I was able to get new studs installed. I tried the c clamp method but those suckers were not budging, so I wailed on it with a hammer until I could get them out. Getting the new studs on was a pain without taking off the hub, but with some light tapping and wiggling I was able to get all the studs through, which I then put lug-nuts on and tightened with a breaker bar about 3 ft long until the stud seated in the the hub. I didn't replace the two studs that were intact, because it was getting late and I need the car today.

I have a leak on both axle seals so I figure Ill just replace both hubs when I pull the axles soon - Where is the best place to get new hubs? Any thing I should avoid (Certain brands?)

With that many studs broken what does the wheel look like? Is there any damage to it because they were not secure properly?

quote Originally posted by Marvin McInnis: There are actually three types that I know of: flat, conical taper (standard on GM cars), and spherical taper. You are correct that you MUST use the correct type specified for the wheels you have mounted ... which is not necessarily the type originally used by the vehicle manufacturer.

See https://www.fiero.nl/forum/F...HTML/089756.html#p12 for links tell you kind of lugs...

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Make sure after you intall new studs, to check the nuts for tightness at least a few times (every 50 miles or so). Many times they will become more seated as you drive and heat/cool cycle them and make the nuts loose.

C-clamp is usually not going to work but "wailing on it" can damage the bearing esp bad if it is an 88. Taking the wheel hub off and putting it in a vise with a nut on the other side will work. GM makes a special tool part # "J29incrediblyexpensive483" specifically for removing wheel studs however a standard 3 leg gear puller can be used to remove studs without removing the hub and without impacting the wheel bearings