Snapped an RE trailing arm bolt.. *UPDATE* With better pictures
#16
#17
Rennlist Junkie Forever
#18
Rennlist Member
#19
Three Wheelin'
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More likely the opposite. The bolt failed by fatigue, as evident by the beachmarking at the top edge of the fracture. This usually indicates insufficient tensioning of the bolt.
Also the area at final fracture is only about 65% of the area of the fastener, which is hard to achieve if the fastener has been tensioned to >70% of its ultimate tensile strength.
Also the area at final fracture is only about 65% of the area of the fastener, which is hard to achieve if the fastener has been tensioned to >70% of its ultimate tensile strength.
Last edited by mikey_audiogeek; 09-30-2012 at 06:15 AM.
#20
Three Wheelin'
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I'm concerned about the mark shown here (circled inred): is there any chance that the bolt wasn't sitting square and flat against this surface? This mark seems to correlate with the oter edge of the fastener shank.
Attachment 668016
Attachment 668016
Last edited by mikey_audiogeek; 12-11-2012 at 05:34 PM.
#21
Three Wheelin'
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...which might correlate with this edge here. I'd be concerned at the dark coloration between this edge and the fracture, seems to indicate insufficient contact.
Attachment 668017
Attachment 668017
Last edited by mikey_audiogeek; 12-11-2012 at 05:34 PM.
#23
Rennlist Junkie Forever
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I'm concerned about the mark shown here (circled inred): is there any chance that the bolt wasn't sitting square and flat against this surface? This mark seems to correlate with the oter edge of the fastener shank.
Attachment 668016
Attachment 668016
TonyG
#24
Rennlist Member
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I think it was about 7-8 years ago this happened on another members car (a gold one) if I remember correctly. It shows it with the wheel tucked up in the body all the way.
#25
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It was it was one of my concerns, it was flush and torqued to RE spec with two torque wrenchs one standard one digital
#26
Three Wheelin'
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Oh well, that's all the easy options ticked off.
Anyway, sorry to hear of the failure, hope you get up and running again soon!
Are you going to send the failed parts to Karl for assessment?
Best regards,
Mike
Anyway, sorry to hear of the failure, hope you get up and running again soon!
Are you going to send the failed parts to Karl for assessment?
Best regards,
Mike
#27
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Thanks, I am going to send the pieces back to Karl, it's important to know what happened for obvious reasons.
#28
Race Director
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I had the same issue with Ground Control shock mounts. After the second failure I upgraded to the Racers Edge mounts. I hope It doesn't happen again, a tow and new tire isn't cheap!