Re: GTV-6, broken lugs, advice needed

[ALfactor@xxxxxxx]

As someone who spends too much time each month looking at failed WAP(wheel 
atttaching parts)  let me take a swing at this.  I preface it by admitting 
that my advise is based on what we recomendations for truck applications.

The most common failure of studs is due to a loosening caused by 
overtightening!  How's that for reverse logic?  try explaining that to a 
mechanic in love with his 3/4" impact gun!

What usually happens is that the nut  is overtightened which stretches the 
stud, causing a loss of clamp load, which actually produces a loose 
condition.  If you look at the broken end of a failed stud you will usually 
see the characteristic "beach marks" where the stud was failing in small 
increments, they are usually polished smooth up to a point where the metal is 
rough and grey looking, which is the point where the stud finally let go.

The recomendation for Class 6-8 vehicles is to replace the studs on either 
side in addition to a broken one, and if two fail to replace all on the wheel 
end.  Of course this is on vehicles with ten studs, but it would seem even 
more critical when you have even fewer.  Besides studs and nuts aren't that 
expensive, (said the salesman).  

Also always torque to to the correct value, and leave the anti-sieze in the 
toolbox.  Torque specifications for WAP are dry.  (at least for trucks). I 
think we have a video on CD if anyone is interested e-mail me and I'll try to 
find a copy.

Off my soapbox for now.

Mitch Fisher
District Sales Manager
ArvinMeritor
Commercial Vehicle Aftermarket
120,000 part numbers and only two 
that fit my '74 Spider.
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