Stud broke - odd coloration - ??
Apr 24, 2007, 08:34 PM
#1
Stud broke - odd coloration - ??
Pics here: http://www.flickr.com/photos/ejevo8/...23644761/show/
I had the studs for an H&R Trak+ 5mm spacer kit installed on my Evo about 1 month ago.
I busted a lug changing wheels for an autox this past weekend. The really odd thing about this is the lug broke while just beginning to tighten it with a torque wrench. I wasn't even applying much pressure when the nut and stud just separated from the head. I was able to hand spin the lug nut back off the stud post that came off.
What I found interesting was the coloration of the exposed metal within the stud and head. Both had this same discoloration on one side of it, and a very dark brown streak through the middle.
Just wondering if others have seen this discoloration of their busted studs? I'm wondering if it means there was a contaminant in the metal or if it was cracked for awhile and exposed the inner metal to weather corrosion.
I had the studs for an H&R Trak+ 5mm spacer kit installed on my Evo about 1 month ago.
I busted a lug changing wheels for an autox this past weekend. The really odd thing about this is the lug broke while just beginning to tighten it with a torque wrench. I wasn't even applying much pressure when the nut and stud just separated from the head. I was able to hand spin the lug nut back off the stud post that came off.
What I found interesting was the coloration of the exposed metal within the stud and head. Both had this same discoloration on one side of it, and a very dark brown streak through the middle.
Just wondering if others have seen this discoloration of their busted studs? I'm wondering if it means there was a contaminant in the metal or if it was cracked for awhile and exposed the inner metal to weather corrosion.
Apr 24, 2007, 11:03 PM
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That's interesting.
The crack propogation of that stud indicates a side-loading. This could have been because you mounted your rim a little off center, and tightened the lugs unevenly, or that your rim spun on the hub and caused side loading... In any case, I would check your other studs to be sure there's no problem.
If it was a simple over-tightening, you would see a spiral crack propogation but this shows that there was a side-sheer.
The crack propogation of that stud indicates a side-loading. This could have been because you mounted your rim a little off center, and tightened the lugs unevenly, or that your rim spun on the hub and caused side loading... In any case, I would check your other studs to be sure there's no problem.
If it was a simple over-tightening, you would see a spiral crack propogation but this shows that there was a side-sheer.
Apr 24, 2007, 11:07 PM
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That's interesting.
The crack propogation of that stud indicates a side-loading. This could have been because you mounted your rim a little off center, and tightened the lugs unevenly, or that your rim spun on the hub and caused side loading... In any case, I would check your other studs to be sure there's no problem.
If it was a simple over-tightening, you would see a spiral crack propogation but this shows that there was a side-sheer.
The crack propogation of that stud indicates a side-loading. This could have been because you mounted your rim a little off center, and tightened the lugs unevenly, or that your rim spun on the hub and caused side loading... In any case, I would check your other studs to be sure there's no problem.
If it was a simple over-tightening, you would see a spiral crack propogation but this shows that there was a side-sheer.
Apr 24, 2007, 11:10 PM
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if you look closesly it seems that the fresh metal in the center was the only thing holding for a while and the discolored area has been cracked for a while... just a thought
Apr 25, 2007, 05:14 PM
#7
I won't be using the spacers at the track, tho.
Originally Posted by LancerEVA06
I was thinking that, or just a defective stud. I've actually seen a few of those sheered at that point, I've come to find out that [normally] it was installed incorrectly.
Originally Posted by newimportowner
Every other stud.........STUD
Thanks for the opinions. I'm going to contact H&R and see what they say. I'll post it up later this week.
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May 2, 2007, 09:49 PM
#8
Sorry - still haven't found time to hit up H&R. I was at the garage today and showed it to the mechanic who put them on. He said it reminded him of hydrogen or oxygen embrittlement, and that some Porsche head? manifold? bolts have a rep for suffering from the same thing.
May 3, 2007, 04:13 AM
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Embrittlement can occur during improper heat treatment of the part. But I don't have the knowledge to tell you if thats what caused this.
My big worry would be if this is a batch problem with the studs you have or a single issue with the one stud. Seems H&R has a good reputation so I would probably go for a single stud replacement. Definitely call them and get the photos to them, it's important for them to know how their products fail in the consumer's hands.
May 5, 2007, 04:18 AM
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Are the evo wheels hubcentric like DSM's? I believe they are in that the center part of the wheel fits in a corresponding male "bump" in the wheel to help locate it and take some up and down loading.
Typically what you find with fastener failures are that if you crack it before failure the cracked portion polishes itself smooth. It shouldn't have time to corrode if you've driven the car lately. Then it will fail. The failure cross section will be dull which we do see.
It is possible that their was a void in manufacturing that stud and it was always cracked. Theirfore it didn't have a chance to wiggle and polish because the portions weren't close enough to do so. Then one day it just failed due to too little cross section.
Luckily you have 5 studs so total failure would be rare. Just keep an eye on them and if you notice a problem the spacers may need to be redesigned to incooperate a hubcentric feature to properly key and locate them on the brake rotor hat to take the loading as the studs really are not designed to do this. The spacer should also be designed to be hubcentric to the wheel so the whole assembly stays "locked" and the fastener only has forces in tension and nothing else. Fasteners work best when used in only tension.
Typically what you find with fastener failures are that if you crack it before failure the cracked portion polishes itself smooth. It shouldn't have time to corrode if you've driven the car lately. Then it will fail. The failure cross section will be dull which we do see.
It is possible that their was a void in manufacturing that stud and it was always cracked. Theirfore it didn't have a chance to wiggle and polish because the portions weren't close enough to do so. Then one day it just failed due to too little cross section.
Luckily you have 5 studs so total failure would be rare. Just keep an eye on them and if you notice a problem the spacers may need to be redesigned to incooperate a hubcentric feature to properly key and locate them on the brake rotor hat to take the loading as the studs really are not designed to do this. The spacer should also be designed to be hubcentric to the wheel so the whole assembly stays "locked" and the fastener only has forces in tension and nothing else. Fasteners work best when used in only tension.
Jun 15, 2007, 04:53 PM
#13
Not sure why I didn't get a notice on your reply here, but I needed to update this...
Yes - wheels are hub centric. Spacers are also hub centric, and when they are on the wheel has no bite on the hubs.
I still have not heard back from H&R. I'm a bit surprised as I thought they are a pretty stand-up operation. I'll hit them up once again for a response.
Yes - wheels are hub centric. Spacers are also hub centric, and when they are on the wheel has no bite on the hubs.
I still have not heard back from H&R. I'm a bit surprised as I thought they are a pretty stand-up operation. I'll hit them up once again for a response.
Jun 22, 2007, 05:32 PM
#14
I'm officially p1$$ed at this point.
I made yet another phone call to H&R about this problem back on June 15th. "Josh" from H&R asked that I email him a link to the photos of the stud. I haven't heard a thing since then.
I did a 2 day track event this past Monday and Tuesday with Patroon BMWCCA at Watkins Glen. Taking the wheels off tonight for an autocross event tomorrow, I get the familiar sensation of the lugnut turning but not quite getting tight. Take the wheel back off and notice the one lug has a small amount of flex in it. As I take off the calipers and start testing the lug again, it slowly bends and breaks off in my hand.
Luckily I have some spares that I ordered, and the stock lug nuts have been easily separated from the broken studs so far.
Beware of H&R quality - this is not good.
I made yet another phone call to H&R about this problem back on June 15th. "Josh" from H&R asked that I email him a link to the photos of the stud. I haven't heard a thing since then.
I did a 2 day track event this past Monday and Tuesday with Patroon BMWCCA at Watkins Glen. Taking the wheels off tonight for an autocross event tomorrow, I get the familiar sensation of the lugnut turning but not quite getting tight. Take the wheel back off and notice the one lug has a small amount of flex in it. As I take off the calipers and start testing the lug again, it slowly bends and breaks off in my hand.
Luckily I have some spares that I ordered, and the stock lug nuts have been easily separated from the broken studs so far.
Beware of H&R quality - this is not good.
Jun 22, 2007, 07:51 PM
#15
Odd thing I noticed after putting one of the spare H&R studs on that I'd ordered along with this kit...
The end of the studs that came with the kit appear to be unfinished inside the middle. They are uneven and wavy, like molten metal, but the outside edge where the threads end are finished. The replacement studs I ordered have a machined finish on the end, with concentric marks in a circular pattern.
I'm having a tough time getting pics to come out in the lighting tonight, so I'll see if I can grab some in daylight hours.
Wonder if I got knock-off studs in my spacer kit. All items were ordered from an official H&R reseller - Options Auto Salon.
The end of the studs that came with the kit appear to be unfinished inside the middle. They are uneven and wavy, like molten metal, but the outside edge where the threads end are finished. The replacement studs I ordered have a machined finish on the end, with concentric marks in a circular pattern.
I'm having a tough time getting pics to come out in the lighting tonight, so I'll see if I can grab some in daylight hours.
Wonder if I got knock-off studs in my spacer kit. All items were ordered from an official H&R reseller - Options Auto Salon.