punish_her

iTrader: (8)

I know this isnt a pure FI question but most that tool arround in the wheel forum dont put down enough power to take their advice seriously. So Im putting this here in hopes I get an experienced answer.

Im putting down just over 600whp and I just switched wheels and lugs. I hand tightend the lugs down to the wheel to the point the mounting surface contacted the rotor. I started to torque and set it initialy to 50ft/lbs. The first lug started to tighten and then turned over and popped out. The Stud sheared of with out clicking. I was like FU@#K.

I continued on thinking well I can at least get the rest torqued down and keep the car parked until I can get new studs. The second lug torqued the third sheared. The fourth and fith torqued fine, the 3 good ones were torqued to 75ft/lbs.

I changed to the other side and continued the same way with hand tightening and torqueing in steps. The fourth one stud on the passanger side sheared. All three stud bits were able to be backed out easily by hand.I went to Nissan and picked up 3 studs and put 2 in the drivers side rear. When I went to retorque in the same pattern as before the second stud on the drivers side sheared. Making it a total of 4 studs sheared. All of the front studs torqued just fine.

Inspecting the stud bits the metal is odd. Its discolored but not corroded. Not a heat tempered discolor but more of a bad metal (slag) was rolled into the Stud stock. The studs only have 13K miles on them and no racing.





Each stud brok off between 4 and 6 thread counts down. This has me scratching my head. I have never used an impact wrench tightening down the lugs. The have never seen higher than 85lbs of TQ. Im not sure that power has any thing to do with it but a 40% failure rate on the rear studs only points to a problem at the rear hubs.

My questions are:

A) What would cause this? Is this a power issue or a poor metal issue? Its just odd that there is a 40% failure rate.

B) Are there OEM length hardened studs that will not shear off? All the NISMOS are showing as extended ad I dont need them, just harder more reliable.

350 Rookie

iTrader: (29)

I always tighten to 100ftlbs. I dont think its a matter of overtightening because even before, ive used a 400ftlb gun on my studs and never broken. Something must have weakend the metal.

Blackbird CPV35

iTrader: (19)

The nismos are crap, I broke 4 of them last year and I just recently switched to ARP wheel studs. The ones for the WRX fit just fine, although you have to take the e-brake cable out in the rear to be able to put the stud behind the hub

this is the cheapest place I could find them

http://www.titanmotorsports.com/arpw...hannelid=FROOG

punish_her

iTrader: (8)

These look longer than the OEM ones. I REALY dont want that. I just dropped some decent coin on spline lugs that wouldnt mess up the wheels. and I dont want to replace them. ARP dont make an OEM 350Z size? Im definately going to look arround to see what I can see.

Yeah my guess is something damaged or the metal had bad spots because the grain in the metal are going in seperate directions from the grey part to the brown part. Not happy about that. Im real leary about ordering all new OEM studs.

doug

iTrader: (5)

i had this problem with my maxima.. but it was mainly because of the retards with the air gun got happy and didn't thread/line up the lug nuts before they went to town

punish_her

iTrader: (8)

Ok I found the meat and potatoes of it. The OEM stud are 43mm long with a M12X1.25 thread pitch and a 14.3X36T serration for the press fit knurling. So now I just need to see if ARP has a 1 for 1 stud to replace it.

Im waiting for their customer service responce to see what they have to say.

Sharif@Forged

iTrader: (92)

Something is not right here. How did you removal the old stud, and install the new one?
Are you sure you are using the correct lugnut and trq level? What you have described, is just not possible, unless you are making an error somewhere. I just can't fathom any possible way to snap 4 studs in the same occurence. We go an entire season of racing with one set of studs, and never had a break or a stripped thread. We use ARP extendeds, but never had one issue with OEM, prior to that.

Give us some more detail on the installation process.

Cloud35

Hmm, I don't want to offend you or anything but are you doing it correctly? Not cross threading when you're putting the lug on? And you are sure the torque wrench is held level and even onto the lug and not kind of crooked right? Is the calibration still good on your torque wrench?

I'm with Sharif, I've never heard of all those studs breaking in one instance.

punish_her

iTrader: (8)

That's what has me scratching my head and frankly verry concerned. This is the first time I've ever had studs shear off like this. There should be no way to snap the stud at the low level of TQ it was set on at 60F. If you look at the threads there is ZERO signs of stripping or cross threading. They were the original OEM installed studs to it was all factory. I was able to I started to drill them to use a back out tool but on the first one it was so loose it zipped down into the tip of the lug and fell into the non threaded portion. All I have now is a rattle. The other ones I was able to back out with little effort or tools. Once I drilled a small shallow hole deep enough to get a 1/8" back out tool tip in I just used my fingers to back it out.

The nuts are the proper M12X1.25 pitch and they are not bottoming out on the lug. You can see how deep the actual stud was in. That was about half way into the lug. I have the McGuard 2 peice spline drive lugs. They put less swear and tear on the wheel and have less friction when torquing down. The ones that torqued were nice and smooth. Im super paranoid when it comes to lugs. I tighten them down by hand until the wheel is completely seated before I put the torque wrench to it.

None of the new ones broke, the second round of breakage was still the old set. I "pressed" in the new lugs. I have a block of Aircraft grade aluminium with a hole in it the size of the stud. I used a long shank lung and torqued it to about 95ft.lbs to set in the knurling. I broke it loose inspected it and torqued it down again to 95. I used a fealer guage to make sure there was no gap between the stud back and the hub.

Alberto

iTrader: (14)

I TQ mine to 90ft/lbs always put em on by hand...many launches and $hit on my car no issues.

punish_her

iTrader: (8)

Yep, thats the surprising thing to me. I know these can take a hell of a beating. Im just thinking its my luck as always. Weird **** happens to me that happens to no one else. Evey thing works out in the end and I learn some interesting tid bits of information.

Jay'Z

iTrader: (118)

Maybe you sprayed your wheel with something that weakened the stud metal.. U been using anything weird on your wheels?

It would seem to me that it broke off at the same spot because that is where the lug nut stops.. And a corrosive liquid prob could seep in the threads just enough to corrode.. Just a shot in the dark..

punish_her

iTrader: (8)

Nothing corrosive besides standard wheel cleaner, car soap, and water. Though I dont soak the wheels them selves in cleaner I know some eventualy works down that way. Yep all the lugs broke in the same place because thats where they stopped bit you would figure the weakest point in a normal peice of metal in in the center or just after the thickest peice. All the stud bits had light to no surface rust but all had some kind of discoloration in the metal that wasnt rust.

REALY messed up. Im still waiting on ARP to see if they have any thing or could make any thing in my spec. Trying to avoid the NISMO's because they are over priced and I think made of the same material. ARP would be my first choice.

punish_her

iTrader: (8)

Does any body know what the underhead length of the NISMO 50mm wheel studs are? It's looking like the 50mm is the overall length but I havnt found any additional information out about them besides the thread pitch, knurl dimension, and length.

I've been in contact with ARP and they are saying they dont have any thing that will fit the dimensions I gave for the exception of the the WRX ones. They are an inch or so longer than I need for my underhead length. They have stopped just short of saying buy a set and cut them down. Still trying to work out if they can just cut what I need.

Definately avoiding getting new lugs since I have ZERO miles on the new lugs I have now.

andypandy

iTrader: (2)

Just throwing out ideas here... Is the wheel cleaner acid based?

punish_her

iTrader: (8)

Nope just the Mcguires wheel/ tire cleaner. If it was ACID based cleaners I would have issues with the front studs breaking as well. Its only been the rear wheels where the studs are breaking. The fronts are just fine as of now.

punish_her

iTrader: (8)

I just sucked it up and went with the ARP Studs and open ended lugs. It was going to cost as much as the new lugs to get the studs cut down to a proper size at a machine shop to use the extended studs. So I just bought the open ended and Im going to sell the new spline drives. I wrote a DIY for the rear replacement since its vastly more complicated than the fronts. The front is a simple knock out put in and set the stud. Look for the rear install in the DIY section.

Im realy hoping it will help others out if they decide to go with the extended stud route.

Cass007

iTrader: (34)

Can't you just cut and bevel the edge of the longer ones with a dremel??

punish_her

iTrader: (8)

Yes and no. A dremel doesnt cut perfectly straight and will cause a decent amount of heat. That may do some thing with the structure I wasnt willing to accept. I was looking for a cold cut that didnt put much heat into the stud and all could be cut the exact same.

If I payed $150 for wheel studs Im not going to jimmy-rig a solution. Just not my style. So I just bought new lugs and will just sell the old ones to help offset the price a little.

EDIT: On a side not the front OEM studs torqued down to 90ft/lbs with no issues. I just checked them today. I didnt have every thing here at home to replace them. The front bolts need some "LUVIN'". The car started to tilt on the jack stands. So Im going to wait for a lift. So the issue with the oem studs was exclusively with the rear wheels. That still has me scratching my head.

Sharif@Forged

iTrader: (92)

One last question. Did you happen to use some kind of anti-seize compound, thread locker, or moly lube on the studs that broke?

For what it's worth, most racers don't use antiseize or any type of lube on studs, becuase it results in very high actual trq loads, and can cause the snaps you just described. 90-95 ft/lbs dry.