The arm assembly from customer complaint (#(b)(4)) was received and identified as a sigle 21st century centurion light system (model 021514, s/n: (b)(4)).
The unit was hung and visually inspected as a system.
After we made out initial visual observations, we performed an in-depth analysis on the failure.
The arm support fitting ((b)(4)) was identified as the failed component.
We inspected the component at the break and found no evidence of porosity or irregular material flow in the area.
In our analysis we observed surface damage consisting of deep circular gouges in the area under the nut attached to the coupling bolt.
This would be indicative of an overtightened condition which would stress the casted aluminum tangs to a point of failure.
We have witnessed this before when a customer attempted to increase the friction level of the suspension arm to minimize horizontal drift.
However, we could not definitely prove this theory in that we only observed the visual incongruity while the stress fractures in the component were not readily apparent.
Note: this report is late because it was sent to the test emdr instead of production.
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