Anyone ever had a wheel come off?

[RSO 34]

I just got back from Lime Rock (minus the NSX unfortunately) after going through a "first time I have ever heard of this" experience. I was coming through the left hander and my right rear wheel came off resulting in the expected spin into the grass. Here is the way the "bolts" looked after getting back into the pits:

Before the inevitable question is posed, rest assured that I did torque the lugs to 80 ft lbs five minutes before going on the track. The car had cooled off for approximately 100 minutes before I torqued them. I ran about 20 minutes of the session doing consistent 1:08-1:09 laps right before this happened. DocJohn and Peter Mills were with me and have not seen anything like this before. Any thoughts?

Here is the video of this little off road adventure:

http://www.imagestation.com/album/?...invite&cmp=EMC-IS_other&creative=album-invite

 

[nsxtasy]

Heard of a wheel coming off? Yes. Heard of a wheel coming off when all the lugs had just been freshly torqued? Nope. VERY strange...

 

[ncdogdoc]

Robert,

Are you the original owner? How long have you owned this car?

My thought would be a severe over torqueing at some point in the past that weakened the studs at the level of the hub, and enough track days by someone who is obviously getting too fast finally stressed them. Why so many failed at the same time I will leave to the materials engineers in the group.

 

[RSO 34]

It is a 96 and I bought it in 99 with 24,000 miles. It now has 75,000 miles and about 25 track days. The brakes were changed last weekend and no visible problems were noted. I had new tires mounted earlier this week but watched them torque all wheels at 80 with a torque stick.

 

[DanO]

Wow! Sorry to hear about this! Happy though, that everyone walked away! What wheels were you running?

DanO

 

[RSO 34]

OEM wheels and tires.

 

[Acura NsX Pilot]

Im sorry to hear about your mis fortune Bob ... I hope everything will be ok. What was the extent of the damage on the car ?

Just saw the video footage...that happened so fast....I was scared watching it.

 

[Jin1976]

Are those studs OEM?

 

[JSMDMD]

Broken stud...

A few months ago after an autocross, I replaced my rear tires (again) and found that one of my studs had broken.
I thought it rather strange, and had it replaced. The lug nuts had been torqued to 80 lbs as well.
Not a comforting thought that this can happen.
I am glad to hear that you are OK though.

Joel 91 Black/Ivory

 

[RSO 34]

The studs were OEM and were the originals.

The damage cosmetically was amazingly minor but my new suspension will need work after dragging on the ground. I won't know more until Pbassjo has a chance to get a good look at it in his shop.

 

[RP-Motorsports]

Thank God it happened where it did!!!! And not on the way home in traffic!


Well from the pic it looks like 2 gave way (under torqued) and then the stress broke the other 3 due to the constant fast left/right of the wheel due to two missing lugs.

I am going to take the opposite stance and say 80 is not enough. I run 90. I have lost lugs and had loose lugs before @ 85 lbs.

 

[nsx1164]

I am going to take the opposite stance and say 80 is not enough. I run 90. I have lost lugs and had loose lugs before @ 85 lbs.

I also run 90 ft-lb lug nut torque on my plus-size wheel setup (17/17 and 17/18) per the recommendations from a well-regarded NSX tech. Haven't lost any yet, but have had loose lugs before @ 80 ft-lb.

 

[NeoNSX]

If you'd intended that spin, I would have said PERFECT 360' !!!

But all jokes aside, you are extremely fortunate. I'm glad you were unhurt, and the damage was relatively minor. Like Acura NsX Pilot said, it happened so quick, but you handled the car extremely well. (plus no off-camera swearing, screaming or crying either. )

 

[Brian2by2]

I had a wheel come off at about 70mph because a stupid tuner shop didn't tighten them down enough. Oddly, the car didnt really vibrate too much or anything...it just kind of happened all at once. My ABS system shut off and I had to use the ebrake and downshifting to slow down...took over 3/8's of a mile!

 

[ak]

This is scary. I'm glad you didn't hurt yourself or others and came out of it with minimal damage. My question now is:

Should wheel studs be something that gets replaced as preventive maintenance? Is there anyway of testing it?

 

[D'Ecosse]

... had new tires mounted earlier this week but watched them torque all wheels at 80 with a torque stick...

They may have used a torque stick, but did they use it properly? It's all too easy to just continue to squeeze after it clicks ...
I would think after all the miles track events you've done I would be suspecting something related to recent activity - i.e. the brakes or tire changes

Glad you're safe & the car doesn't look like it suffered any major damage either.

I thought it was amusing in the video at the end when you immediately restarted & tried to go! (not amusing because of the misfortune - I smiled at the instant racer reaction to want to get back out there - hope that comes across the way it was intended)

 

[Arata]

Glad you are OK.
I would suspect Honda would know what torque works with the studs.
Over torqueing them may be part of the problem, bolts that are used again and again are stressed and fatigue. For people changing wheels often a regular replacement of these studs will most likely solve the problem.
Some info on the web.
Basic info

Software

Examples of failures

More examples of types of failures

 

[RP-Motorsports]

Yeah I too liked the re-start of the motor! I would do the same thing wondering if the spin was due to a blown motor (oil). I would have checked the engine as well.

Another reason he restarted it, was to attempt to move the car a bit more out of harms way??

 

[nsxtasy]

I would suspect Honda would know what torque works with the studs.

I agree. I have always torqued my NSX lug nuts to 80 lb-ft, and even have had my torque wrench calibrated. I've never had a problem.

 

[NSXNEV]

NSXNEV

Hi Bob-

WOW! Overall, I think you handled the situation exceptionally. Glad you are okay. Reminded me of Gilles Villeneuve trying to continue with the race even without his right rear wheel (South Africa, 1979)!

Cheers-

Nev

 

[RSO 34]

THANKS!

Thanks to everyone for the good thoughts.

After speaking with numerous non-NSX drivers back at Lime Rock today (I went back today for moral support for DocJohn and Peter Mills), many told me that they change the studs every 2 years because of their track events. I had never really heard any NSXers talk about that but I am definitely replacing all 20 now and will do so every 2 year now as a preventative measure.

Yes, my initial reaction was to restart and immediately get back out on the track. I felt like an idiot when I looked in the mirrors to see if it was clear and saw my wheel upright in the grass. We figured out that the wheel sheared and went under the rotor and I slid on top of the wheel into the grass where the wheel came out.

What the video did not show is me calmly turning off the camera before climbing out of the car and running up the embankment in case of fire (the exhaust and rotors were extremely hot and obviously laying on top of the grass) or someone going off in the event I trailed any fluids or parts.

 

[JGuidry]

It happened to me on the same wheel.

Over torqued Lugs!!

I thought they were over torqued, but it turns out they were under torqued.

-Jonathan

 

[KGP]

Heard of a wheel coming off when all the lugs had just been freshly torqued? Nope. VERY strange...

Mine ALMOST did, but I caught it just in time. I had just mounted new tires, and personally put the wheels back on [torque to 80#]. Drove the car for a day, and when on the highway I noticed a bit of a wobble. Started getting more noticeable in a very short time. Fortunately, I still had my sockets and torque wrench in the car. I have no idea why this hapened.

 

[apapada]

Lug studs break like this when they have been torqued and retorqued many times. Eventually they fail as everytime you torque them you are putting quite a stress on each of them. Overtorquing them (>80 ft.lbs in our case) will just accelerate their failure. If one is using OEM studs (vs. aftermarket longer ones for instance) and Honda says 80 ft.lbs, one should stick to those specs, period.

 

[nsxtasy]

I'm expecting to see John Vasos, Director of Service and Parts at Acura of Brookfield, the Midwest's leading servicer of stock, aftermarket, and race-prepped NSXs, this Monday. I'll ask him about his experience with this issue.