Here's a closer shot of the joint. Note the large round joint on the left, with the remnant of the threaded portion - badly bent - coming out the bottom (I'm assuming it just freely rotated to that position).
I had just gotten the car back from the 7,500 mile service a few days before. Plus I had checked the torque after the previous track day, but that was at maybe 5,000 miles. So I'm reasonably confident, but not 100%.MattG said:Andy - how confident are you that your toe link joint was properly torqued?
No. AFAIK this is basically they way it should fail in case of an overload situation and protect the subframe from further damage.MattG said:Anyway, the odd thing was the rear inner toe link on that impacted corner. With all the talk about this joint, checking its torque and all, I'd come to the belief that if it fails, it would be due to shear of the bolt itself.
I see your point; I'm an engineer and it's like Nak says, I'm using this term not to indicate fault with the design but just that the part 'broke'. I strongly believe that this failure was caused by the impact to the rear wheel, as evidenced by other damage in that area. I mention the wheel dug into the dirt; I only mentioned that because I wondered if that might have influenced how this joint failed, not that it failed in the first place.JonOrangeElise said:And can anyone fairly call this a "failure"? To me, a suspension part "failure" happens suddenly, catastrophically, during regular driving (on the track or otherwise). No, in my world of definitions once you have a major impact, parts are forgiven if they break apart here and there. (That said, I would argue that if some type of passive safety system failed -- one that was designed to behave a certain way during impacts -- then this would in fact be a failure.)
It should "fail" exactly the way that it did.MattG said:I don't see how hitting a wall would cause this type of failure? It looks like the inner attachment bolt was loose and was able to stretch as the inner joint pulled it away from the subframe, until it had rotated enough that the toe link could then buckle, causing the failure here. The thing is, it shouldn't happen like this!
The line of force does pass through the center of the ball. But the center of the ball is spaced away from the chassis, causing a bending moment about the ball joint's mounting bolt. So the ball joint must withstand a rotational force (about the mounting stud) as well as a lateral force (shear on the stud). The Heim joint does not have the rotational forces...R T said:Tim, are you saying the line of force does not intersect the center of the ball on the stock setup?
I stand corrected.MattG said:I see your point; I'm an engineer and it's like Nak says, I'm using this term not to indicate fault with the design but just that the part 'broke'. .