RE: GTV-6, broken lugs, advice needed

["Ian Lomax" <sfalfisto@xxxxxxxxx>]

> I noticed yesterday that two of the lugs on my right front wheel are 
> broken off.  I haven't done anything weird or abusive, but I did 
> install new brake discs (and lugs) about 1000 miles ago.
> 
> My questions are:
> 1) Why on earth did this happen?  (A Miata-owning aquaintance wasn't 
> surprised and said he's seen this happen before, but I can't see what 
> they cause could possibly be.)

What did you torque the lug nuts to?  If you didn't overtorque them, I'd
say you've got some bad studs.
 
> 2) How dangerous is it to drive (conservatively) with two of five 
> lugs broken off on a hub-centric wheel?

Hubcentric only means the wheel is centered by the hub, but it's held on
by the lugs and nuts.  I wouldn't drive it until you solve the problem,
one hard turn and the other three might give up the ghost.
> 
> 3) Even if the answer to #2 is "pretty safe," what are the odds of 
> additional lugs randomly breaking off over the next 500 miles?

Well, at this rate I'd say the odds are 1 in 5 based on your sample
size.  Not good in my book, and I bet the failure rate will increase
with the additional stress each lug is now under.

I would go find new lugs from a reputable source, and make sure they are
installed correctly.

Good luck,
Ian Lomax
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