Wasn't a stub axle.. was the 2 bolts that hold the steering arm to the right
side suspension. Opinions vary on whether as Grade 8, that was a
contributing factor... but the week before it had been raced at a very rough
Blackhawk Farms (before the repave).
http://www.thicko.com/ReadRatDeadRat.htm
-----Original Message-----
From: spridgets-bounces@autox.team.net
[mailto:spridgets-bounces@autox.team.net] On Behalf Of Mark Haynes
Sent: Monday, February 16, 2009 11:04 AM
To: spridgets@autox.team.net
Subject: Re: [Spridgets] Ebay Lower Control Arms
Nope, not the welds (hopefully)- The weak link is the 1/2"-20 Threads! think
about it- ~375lbs (750 lbs/2 joints) in shear on an extended shaft with a
root
diameter of 7/16" (being generous), so at rest there's a shear force of 857
lbs (no problem). Then hit a bump/chuck hole, etc. realizing that the shear
strength is ~40% of tensile (again conservative), assuming an impulse of at
least 1/4 the weight of the car and driver(~400lbs)/5 milliseconds gives an
instantaneous loading of 8375lbs. Average yield strength of Grade 2 bolts
(and
low end heim joints) is 36ksi. multiply by .4375 for cross sectional area,
again by .4 for shear loading, and it yields at 6773 lbs. That calc is
rough,
and not even taking into consideration the horizontal loading (which is much
greater due to the mass of the vehicle).
I'd not drive on such a thing, remember what happened to Flounder with Red
Rat
Bastard at speed when he broke a stub axle? Thankfully, he was wearing a
helmet-I don't on the street, do you?
Mark Haynes
HAN6L12779
_______________________________________________
Support Team.Net http://www.team.net/donate.html
http://www.team.net/archive
http://autox.team.net/mailman/listinfo/spridgets
|