Inspecting Lower Control Arm Ball Joint Tapered Seat After Front End Impact (Accident Situation, Wheel Damage From Curb Impact, Etc.)

The front lower control arm ball joint taper in the aluminum steering knuckle may be damaged by severe impacts, such as crash situations or curb impacts. This may result in a subsequent loosening of the ball joint nut.

In severe impacts or crashes, the loads into the suspension may result in deformation in the ball joint taper and subsequent loosening of the ball stud. This condition is typically accompanied by damage to other chassis components in the crash force path (wheel bearing/hub, tire, wheel, etc.). When vehicles are being repaired for such conditions, the steering knuckle, front lower control arm, and specifically, the ball joint stud taper, must always be inspected.

As part of any service procedure to the front suspension necessitated by "damaged" suspension components (such as replacement of the wheel, the wheel bearing/hub, or other suspension components due to a curb impact, or when wheel alignment has been significantly affected), the knuckle, ball joint, and lower control arm should be inspected and replaced as necessary. If the ball joint stud nut is loose, then replace the knuckle and ball joint stud per the service procedures.

In addition to the external visual inspection of the lower control arm and steering knuckle for damage, the steering knuckle ball stud taper must be inspected to verify that damage to the steering knuckle, at the taper joint, has not occurred. The joint should be disassembled and the steering knuckle carefully examined. If the taper hole is oblong or there are signs of deformation on the top or bottom of the steering knuckle boss , the steering knuckle and ball joint stud nut should be replaced After replacement, tighten all joints to specifications.