NHTSA complaint #11747836

Owner complaint summary

While driving a 2023 Chevrolet Bolt during a turn maneuver, one of the two bolts (nearest the driver) holding the lower control arm (to the vehicle on the front driver side) sheared completely. An inspection of the joint suggests a fatigue failure likely due to inadequate factory assembly clamping force (pretension). Because the joint lacked the required factory torque, the joint interface slipped under normal operational loads, shifting cyclic shear and bending forces directly onto the bolt threads and shank—loads the fastener was not designed to carry alone—resulting in a fatigue fracture. The sudden failure of a primary front suspension control arm fastener while the vehicle is in motion is a safety hazard. It causes steering instability and risks a loss of vehicle control. The problem was confirmed and repaired by an independent service center/mechanic who replaced the control arm sub-assembly. The sub-assembly has been retained and is available for inspection upon request. The vehicle and failed component have not yet been inspected by the manufacturer, police, or insurance representatives. There were no warning lamps, dashboard messages. We had noticed the tire was rubbing on the wheel well during certain maneuvers for months beforehand, but we thought the wheel well liner was sagging. In hindsight this was due to the control arm not being firmly held by the bolt. When the bolt sheared my wife reported hearing a loud pop, the vehicle was still drivable but unstable, as soon as we realized something was severely wrong we took it slowly to the nearest mechanic where they repaired the problem.