There was a discussion of this problem but I don't remember where I read it. But, I believe it was restricted to the very early cars or the late model GT5s(Euro models) that did not have the reinforcing plate added to the rear frame where the lower control arms mounted to. The nut would simply sink/pull through a weakened frame rail on a strong jolt or over-tightening.
I am sure someone will chime in with the details?
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